Neurosurgery Practice QnA Flashcards

Question 1

Q

Regarding the pathophysiology of myasthenia gravis, what is/are the possible mechanisms by which acetylcholine receptor antibodies interfere with neuromuscular transmission?
A. Binding to the acetylcholine receptor and blocking the binding of
acetylcholine
B. Cross-linking acetylcholine receptors, thereby increasing their rate of
internalization
C. Binding of complement resulting in destruction of the muscle end plate
D. All of the above
E. None of the above

Answer

A

A. Binding to the acetylcholine receptor and blocking the binding of
acetylcholine
B. Cross-linking acetylcholine receptors, thereby increasing their rate of internalization
C. Binding of complement resulting in destruction of the muscle end plate
D. All of the above
E. None of the above
D. All of the above

All three are mechanisms of anti-acetylcholine receptor antibodies.

Question 2

Q

All of the following statements are correct regarding the medial lemniscus EXCEPT:
A. Near the sensory decussation, its blood supply comes from the anterior spinal
artery.
B. The medial lemniscus can be found in close proximity to the anterolateral
tract in the medulla. Its somatotopy in the pons is such that leg fi bers are
lateral to arm fi bers.
C. The fi bers of the medial lemniscus arise from the cuneate and gracile nuclei.
D. Brainstem lesions involving medial lemniscus fi bers usually include adjacent
structures, resulting in motor and sensory losses.
E. None of the above statements are correct

Answer

A

A. Near the sensory decussation, its blood supply comes from the anterior spinal artery.
B. The medial lemniscus can be found in close proximity to the anterolateral tract in the medulla. Its somatotopy in the pons is such that leg fibers are lateral to arm fibers
C. The fibers of the medial lemniscus arise from the cuneate and gracile nuclei.
D. Brainstem lesions involving medial lemniscus fibers usually include adjacent structures, resulting in motor and sensory losses.
E. None of the above statements are correct.

B. The medial lemniscus can be found in close proximity to the anterolateral tract in the medulla. Its somatotopy in the pons is such that leg fibers are lateral to arm fibers

The medial lemniscus (ML) is widely separated from the anterolateral system
(ALS) in the medulla. In fact, ML and ALS fi bers receive diff erent blood supplies
in the medulla. In the midbrain and pons, the ML and ALS are in close proximity
and receive similar blood supplies.

The medial lemniscus (ML) is widely separated from the anterolateral system (ALS) in the medulla. In fact, ML and ALS fibers receive different blood supplies in the medulla. In the midbrain and pons, the ML and ALS are in close proximity and receive similar blood supplies.

Question 3

Q

All the following findings are associated with the abnormality seen on the scan shown here EXCEPT:
A. Ankylosing spondylitis
B. Positive FABER test
C. Positive thigh thrust
D. Pain upon internal rotation of the hip
E. Positive thigh compression text

Answer

A

A. Ankylosing spondylitis
B. Positive FABER test
C. Positive thigh thrust
D. Pain upon internal rotation of the hip
E. Positive thigh compression text

D. Pain upon internal rotation of the hip

The CT scan represents sclerosis of the sacroiliac (SI) joint, which may be seen
in ankylosing spondylosis. This is representative of the diagnosis of sacroiliitis.
Clinically the patient usually presents with SI joint pain and on exam has tenderness along the SI joint with compression as well as a positive thigh thrust
and thigh compression exam and a positive fl exion, abduction, and external rotation (FABER) test. Pain upon internal rotation of the hip is characteristic of hip
joint dysfunction or disease.

The CT scan represents sclerosis of the sacroiliac (SI) joint, which may be seen in ankylosing spondylosis. This is representative of the diagnosis of sacroiliitis. Clinically the patient usually presents with SI joint pain and on exam has ten- derness along the SI joint with compression as well as a positive thigh thrust and thigh compression exam and a positive flexion, abduction, and external ro- tation (FABER) test. Pain upon internal rotation of the hip is characteristic of hip joint dysfunction or disease.

Question 4

Q

Which of the following lines at the craniocervical junction extends from the basion to the opisthion?
A. McRae’s line
B. McGregor’s line
C. Chamberlain’s line
D. Wackenheim’s line
E. Anterior marginal line

Answer

A

A. McRae’s line
B. McGregor’s line
C. Chamberlain’s line
D. Wackenheim’s line
E. Anterior marginal line

McRae’s line is from the basion to the opisthion.

Question 5

Q

The somatotopic arrangement in the ventral horn is such that the
A. fl exors are dorsal to extensors and limbs are medial to trunk.
B. extensors are dorsal to fl exors and limbs are medial to trunk.
C. fl exors are dorsal to extensors and limbs are lateral to trunk.
D. extensors are dorsal to fl exors and limbs are lateral to trunk.
E. None of the above

Answer

A

A. flexors are dorsal to extensors and limbs are medial to trunk.
B. extensors are dorsal to flexors and limbs are medial to trunk.
C. flexors are dorsal to extensors and limbs are lateral to trunk
D. extensors are dorsal to flexors and limbs are lateral to trunk.
E. None of the above

C. flexors are dorsal to extensors and limbs are lateral to trunk

It is helpful to remember that this pattern of somatotopy can be appreciated in
the descending motor pathways: those that are concerned with fl exor musculature (corticospinal tract and rubrospinal tract) lie dorsal to those tracts concerned with extensor musculature.

It is helpful to remember that this pattern of somatotopy can be appreciated in the descending motor pathways: those that are concerned with flexor muscu- lature (corticospinal tract and rubrospinal tract) lie dorsal to those tracts con- cerned with extensor musculature.

Question 6

Q

All of the following techniques may be used to aid in identifying the level of interest in a thoracic diskectomy procedure EXCEPT:
A. Intraoperative lateral fl uoroscopy with counting levels starting from the
sacrum and moving rostral with midline needle localizers
B. Intraoperative anteroposterior (AP) fl uoroscopy with counting levels starting
from the 12th rib and moving rostral with midline needle localizers
C. Intraoperative AP fl uoroscopy with counting levels starting from the fi rst rib
and moving caudal with midline needle localizers
D. Neuronavigation with skin surface fi ducial registration
E. Neuronavigation with spinal bony landmark registration within the proximity of the level of interes

Answer

A

A. Intraoperative lateral fl uoroscopy with counting levels starting from the sacrum and
moving rostral with midline needle localizers
B. Intraoperative anteroposterior (AP) fluoroscopy with counting levels starting from the 12th rib and moving rostral with midline needle localizers
C. Intraoperative AP fl uoroscopy with counting levels starting from the first rib and moving caudal with midline needle localizers
D. Neuronavigation with skin surface fiducial registration
E. Neuronavigation with spinal bony landmark registration within the proximity of the level of interest

D. Neuronavigation with skin surface fiducial registration

Although skin surface fiducial registration is commonly used in brain neuronav- igation, it is not very effective in the spine due to the parallax that is seen from registering on the skin and attempting to navigate at the level of the bone, which tends to be significantly deeper than the level of the skin. The other techniques described for localization are effective in identifying the level of interest in that the thoracic spine adequately.

Question 7

Q

The MRI scan shown here represents an opportunistic infection in a 25-year-old man with acute myelogenous leukemia. All the following statements are true EXCEPT:
A. Pathology reveals pleomorphic short and wide septate hyphae.
B. It can be treated with Cancidas, voriconazole, and AmBisome.
C. It causes hemorrhagic necrosis and ischemic strokes.
D. The organism originates in the soil.
E. It may be seen with an immunocompromised patient

Answer

A

A. Pathology reveals pleomorphic short and wide septate hyphae
B. It can be treated with Cancidas, voriconazole, and AmBisome.
C. It causes hemorrhagic necrosis and ischemic strokes.
D. The organism originates in the soil.
E. It may be seen with an immunocompromised patient.

A. Pathology reveals pleomorphic short and wide septate hyphae

Rhinocerebral mucormycosis on pathology reveals pleomorphic short and wide nonseptate hyphae. It can be treated with Cancidas, voriconazole, and AmBisome. It may cause hemorrhagic necrosis and ischemic strokes.

Question 8

Q

Somatic motor eff erents to the urethral sphincter are located in
A. intermediolateral cell columns of the sacral cord.
B. Onuf’s nucleus.
C. Barrington’s nucleus.
D. All of the above
E. None of the above

Answer

A

A. intermediolateral cell columns of the sacral cord.
B. Onuf’s nucleus.
C. Barrington’s nucleus.
D. All of the above
E. None of the above

B. Onuf’s nucleus.

Somatic motor eff erents to the sphincter are located in the ventral lateral area
of Onuf’s nucleus. Sacral parasympathetics to the bladder are located in intermediolateral cell columns of the sacral cord. Barrington’s nucleus is also
known as the pontine micturition center and is responsible for initiating the
process of micturition.

Somatic motor efferents to the sphincter are located in the ventral lateral area of Onuf’s nucleus. Sacral parasympathetics to the bladder are located in in- termediolateral cell columns of the sacral cord. Barrington’s nucleus is also known as the pontine micturition center and is responsible for initiating the process of micturition.

Question 9

Q

Cerebral ischemia begins when cerebral perfusion pressure (CPP) falls below
A. 100 mm Hg.
B. 75 mm Hg.
C. 50 mm Hg.
D. 23 mm Hg.
E. 8 mm Hg.

Answer

A

A. 100 mm Hg.
B. 75 mm Hg.
C. 50 mm Hg.
D. 23 mm Hg.
E. 8 mm Hg.

C. 50 mmHg

Cerebral ischemia begins when CPP falls below 50 mmHg

Cerebral ischemia begins when CPP falls below 50 mm Hg.

Question 10

Q

Regarding the anatomy near the cavernous sinus, the borders of the clinoidal triangle are cranial nerves
A. I and II.
B. II and III.
C. III and IV.
D. IV and V.
E. None of the above

Answer

A

A. I and II.
B. II and III.
C. III and IV.
D. IV and V.
E. None of the above

B. II and III.

The clinoidal triangle is defi ned by the medial border of the optic nerve medially and the oculomotor nerve laterally

The clinoidal triangle is defined by the medial border of the optic nerve medi-ally and the oculomotor nerve laterally.

Question 11

Q

Which of the following is FALSE regarding myasthenia gravis?
A. The fi rst presentation is usually weakness of the extraocular muscles.
B. Weakness fl uctuates and fatigues over the course of the day.
C. Speech may be hypernasal or hoarse in some patients.
D. It may present with a head drop.
E. Dysphagia is worst at breakfast and improves during the course of the day

Answer

A

A. The fi rst presentation is usually weakness of the extraocular muscles.
B. Weakness fl uctuates and fatigues over the course of the day.
C. Speech may be hypernasal or hoarse in some patients.
D. It may present with a head drop.
E. Dysphagia is worst at breakfast and improves during the course of the day

E. Dysphagia is worst at breakfast and improves during the course of the day.

Dysphagia in myasthenia gravis is fatigable, and the patient often relates a history of little diffi culty with breakfast, moderate diffi culty with lunch, and inability to eat in the evening.

Dysphagia in myasthenia gravisis fatigable, and the patient often relatesa history of little difficulty with breakfast, moderate difficulty with lunch, and inability to eat in the evening.

Question 12

Q

All of the following are true of polymyositis EXCEPT:
A. It involves a symmetric weakness of proximal limb and trunk muscles.
B. Its onset is insidious.
C. Ocular muscles are usually spared.
D. Muscles are not tender to palpation.
E. Skin changes typically occur before muscle abnormalities.

Answer

A

A. It involves a symmetric weakness of proximal limb and trunk muscles.
B. Its onset is insidious.
C. Ocular muscles are usually spared.
D. Muscles are not tender to palpation.
E. Skin changes typically occur before muscle abnormalities.

Skin changes precede muscle abnormalities in dermatomyositis (DM). Poly- myositis (PM) is diagnosed by fibrillation potentials on electromyography (EMG) and elevated creatine phosphokinase (CPK) levels (higher than those for DM). In polymyositis, there is widespread single-fiber necrosis, and T cells with macrophages may be found in the muscle fibers. PM is the most frequent inflammatory myopathy.

Question 13

Q

Protein 14-3-3 is elevated in the CSF in which of the following conditions?
A. Creutzfeldt-Jakob disease
B. Demyelinating disease
C. Head trauma
D. Meningoencephalitis
E. All of the above

Answer

A

A. Creutzfeldt-Jakob disease
B. Demyelinating disease
C. Head trauma
D. Meningoencephalitis
E. All of the above

Protein 14-3-3 is elevated in the cerebrospinal fluid (CSF) with destructive diseases of the central nervous system (CNS). This protein is sensitive for Creutzfeldt-Jakob disease, but not specific.

Question 14

Q

Which of the following statements is most accurate regarding the nerve supplying the teres minor muscle?
A. It has a contribution from the lateral cord.
B. It is an extension of the posterior cord.
C. Ventral rami C8 and T1 are major contributors to this nerve.
D. It is derived from the same cord as the musculocutaneous nerve.
E. None of the above

Answer

A

A. It has a contribution from the lateral cord.
B. It is an extension of the posterior cord.
C. Ventral rami C8 and T1 are major contributors to this nerve.
D. It is derived from the same cord as the musculocutaneous nerve.
E. None of the above

The posterior cord gives rise to the axillary nerve and the radial nerve as its terminal branches.

Question 15

Q

The pterion is formed by the junction of the all of the following EXCEPT:
A. Frontal bone
B. Sphenoid bone
C. Zygomatic bone
D. Temporal bone
E. Parietal bone

Answer

A

A. Frontal bone
B. Sphenoid bone
C. Zygomatic bone
D. Temporal bone
E. Parietal bone

The pterion is located about two fingerbreadths above the zygomatic arch, and a thumb’s breadth behind the frontal process of the zygomatic bone; however, the zygomatic bone does not form the pterion.

Question 16

Q

Which of the following is FALSE regarding the sonic hedgehog (SHH) gene?
A. SHH has been found to have the critical roles in development of the limb and midline structures in the brain and spinal cord.
B. Mutations in the human SHH gene, cause holoprosencephaly type 3 as a result of the loss of the ventral midline.
C. The SHH transcription pathway has been linked to the formation of embryonic cerebellar tumors such as medulloblastoma.
D. SHH has been shown to act as an axonal guidance cue: SHH attracts retinal ganglion cell axons at high concentrations and repels them at lower concentrations
E. SHH plays a critical role in the induction of the fl oor plate and diverse ventral cell types within the neural tube.

Answer

A

A. SHH has been found to have the critical roles in development of the limb and midline structures in the brain and spinal cord.
B. Mutations in the human SHH gene, cause holoprosencephaly type 3 as a result of the loss of the ventral midline.
C. The SHH transcription pathway has been linked to the formation of embryonic cerebellar tumors such as medulloblastoma.
D. SHH has been shown to act as an axonal guidance cue: SHH attracts retinal ganglion cell axons at high concentrations and repels them at lower concentrations
E. SHH plays a critical role in the induction of the fl oor plate and diverse ventral cell types within the neural tube.

SHH has been found to have the critical roles in development of the limb and midline structures in the brain and spinal cord. Mutations in the human SHH gene cause holoprosencephaly type 3 as a result of the loss of the ventral mid- line. SHH is secreted at the zone of polarizing activity located on the posterior side of a limb bud in an embryo. The SHH transcription pathway has also been linked to the formation of embryonic cerebellar tumors such as medulloblasto- ma. SHH has been shown to act as an axonal guidance cue: SHH attracts retinal ganglion cell axons at low concentrations and repels them at higher concentra- tions. SHH plays a critical role in the induction of the floor plate and diverse ventral cell types within the neural tube.

Question 17

Q

Regarding infection in a trauma patient with the X-ray shown here, the most common pathogen is
A. Staphylococcus aureus.
B. Pseudomonas.
C. Proteus.
D. Streptococcus pneumoniae.
E. Escherichia coli.

Answer

A

A. Staphylococcus aureus.
B. Pseudomonas.
C. Proteus.
D. Streptococcus pneumoniae.
E. Escherichia coli.

Afterbasilarskullfractures,themostcommonpathogenisStreptococcuspneu- moniae, and the infection usually occurs within the first few days.

Question 18

Q

Which of the following is incorrect regarding the zona incerta?
A. It is a zone of gray matter between the thalamic and lenticular fasciculi.
B. It is composed of cells that are continuous laterally with the thalamic reticular nucleus.
C. Unlike the thalamic reticular nucleus, the neurons of this zone do not display immunoreactivity for the calcium binding protein calbindin D-28k.
D. It receives corticofugal fi bers from the precentral cortex.
E. All of the above statements are correct.

Answer

A

A. It is a zone of gray matter between the thalamic and lenticular fasciculi.
B. It is composed of cells that are continuous laterally with the thalamic reticular nucleus.
C. Unlike the thalamic reticular nucleus, the neurons of this zone do not display immunoreactivity for the calcium binding protein calbindin D-28k.
D. It receives corticofugal fi bers from the precentral cortex.
E. All of the above statements are correct.

The zona incerta is a zone of gray matter between the thalamic and lenticu- lar fasciculi. It is composed of cells that are continuous laterally with the tha- lamic reticular nucleus. Unlike the thalamic reticular nucleus, the neurons of this zone display immunoreactivity for the calcium binding protein calbindin D-28k. It receives corticofugal fibers from the precentral cortex.

Question 19

Q

All the following are potential contraindications for vagal nerve stimulation placement EXCEPT:
A. Upper cranial nerve deficits
B. Presence of a single vagus nerve only
C. Cardiac arrhythmias
D. Lung disease
E. Ulcer

Answer

A

A. Upper cranial nerve deficits
B. Presence of a single vagus nerve only
C. Cardiac arrhythmias
D. Lung disease
E. Ulcer

While lower cranial nerve dysfunction may be a relative contraindication for vagal nerve stimulation, upper cranial nerve deficits do not represent such a contraindication.

Question 20

Q

The anterior loop of the internal carotid artery lies in the fl oor of this triangle
A. Lateral triangle
B. Anterior lateral triangle
C. Parkinson’s triangle
D. Anterior medial triangle
E. None of the above

Answer

A

A. Lateral triangle
B. Anterior lateral triangle
C. Parkinson’s triangle
D. Anterior medial triangle
E. None of the above

Question 21

Q

Jitter is best described as
A. synchronous muscle fi ber activation between fi bers of diff erent motor units.
B. a difference in timing of muscle fi ber activation between two fi bers in a single motor unit.
C. a diff erence in timing of muscle fi ber activation between two fi bers of different motor units.
D. the complete failure of neuromuscular transmission at one muscle fi ber in a pair.
E. None of the above

Answer

A

A. synchronous muscle fi ber activation between fi bers of diff erent motor units.
B. a difference in timing of muscle fiber activation between two fi bers in a single motor unit.
C. a diff erence in timing of muscle fi ber activation between two fi bers of different motor units.
D. the complete failure of neuromuscular transmission at one muscle fi ber in a pair.
E. None of the above

Question 22

Q

Ataxia may be seen in all of the following syndromes EXCEPT:
A. synchronous muscle fi ber activation between fi bers of diff erent motor units.
B. a difference in timing of muscle fi ber activation between two fi bers in a single motor unit.
C. a diff erence in timing of muscle fi ber activation between two fi bers of different motor units.
D. the complete failure of neuromuscular transmission at one muscle fi ber in a pair.
E. None of the above

Answer

A

A. synchronous muscle fi ber activation between fi bers of diff erent motor units.
B. a difference in timing of muscle fi ber activation between two fi bers in a single motor unit.
C. a diff erence in timing of muscle fi ber activation between two fi bers of different motor units.
D. the complete failure of neuromuscular transmission at one muscle fi ber in a pair.
E. None of the above

Weber’ssyndromeinvolvesthebaseofthemidbrain.ItischaracterizedbyCN III palsy with crossed hemiplegia. All other syndromes mentioned may have ataxia as part of the clinical findings.

Question 23

Q

Which of the following is the least common complication of vagal nerve stimulation placement in the pediatric population?
A. Hoarseness
B. Coughing
C. Shortness of breath
D. Nausea
E. Increased drooling

Answer

A

A. Hoarseness
B. Coughing
C. Shortness of breath
D. Nausea
E. Increased drooling

Question 24

Q

A lesion of which of the following structures would most significantly impair
memory?
A. Amygdala
B. Fornix
C. Dorsomedial nucleus of the thalamus
D. Mammillary body
E. Area 44

Answer

A

A. Amygdala
B. Fornix
C. Dorsomedial nucleus of the thalamus
D. Mammillary body
E. Area 44

Lesions of the dorso medial nucleus of the thalamus,hippocampus,ortemporal cortex cause memory impairment.

Question 25

Q

Which of the following is NOT associated with the findings on this X-ray?
A. Weakness of hand intrinsic flexors
B. Horner’s syndrome
C. Raynaud’s syndrome
D. Traction meningocele
E. Ulnar paresthesias

Answer

A

A. Weakness of hand intrinsic flexors
B. Horner’s syndrome
C. Raynaud’s syndrome
D. Traction meningocele
E. Ulnar paresthesias

The X-ray shows a cervical rib, usually associated with ulnar nerve weakness and paresthesia, Raynaud’s syndrome, and traction meningocele.

Question 26

Q

Bannayan–Riley–Ruvalcaba syndrome is associated with all the following
EXCEPT:
A. Multiple subcutaneous lipomas
B. Macrocephaly
C. Hemangiomas
D. Intracranial arteriovenous malformations
E. Capillary malformation or “port-wine stain

Answer

A

A. Multiple subcutaneous lipomas
B. Macrocephaly
C. Hemangiomas
D. Intracranial arteriovenous malformations
E. Capillary malformation or “port-wine stain

Bannayan–Riley–Ruvalcaba’s syndrome (BRRS) is a rare overgrowth disorder with occurrence of multiple subcutaneous lipomas, macrocephaly, and he- mangiomas. The disease is inherited in an autosomal dominant fashion, but sporadic cases have been seen. The syndrome belongs to a family of hamar- tomatous polyposis syndromes, which includes Peutz–Jeghers’s syndrome, juvenile polyposis, and Cowden disease. Mutation of the PTEN gene is associ- ated with this syndrome, Cowden disease, Proteus syndrome, and Proteus-like syndrome. These four syndromes are referred to as PTEN hamartoma-tumor syndromes. Intracranial arteriovenous malformations represent a rare feature of BRRS. Capillary malformation or “port-wine stain,” is a cutaneous vascular anomaly that initially appears as a red macular stain that darkens over time. It also occurs in several combined vascular anomalies that exhibit hypertrophy, such as Sturge–Weber’s syndrome and Klippel–Trénaunay’s syndrome.

Question 27

Q

Where is the extreme capsule located?
A. Between the claustrum and the putamen
B. Between the claustrum and the insular cortex
C. Between the putamen and the globus pallidus externus
D. Between the globus pallidus externus and the globus pallidus internus
E. Above the caudate nucleus

Answer

A

A. Between the claustrum and the putamen
B. Between the claustrum and the insular cortex
C. Between the putamen and the globus pallidus externus
D. Between the globus pallidus externus and the globus pallidus internus
E. Above the caudate nucleus

The external capsule is located between the claustrum and the putamen. The extreme capsule is located between the claustrum and the insular cortex.

Question 28

Q

Which of the following neurotransmitters promotes penile erection?
A. Serotonin
B. Dopamine
C. Noradrenaline
D. All of the above
E. None of the above

Answer

A

A. Serotonin
B. Dopamine
C. Noradrenaline
D. All of the above
E. None of the above

Serotonin pathways inhibit copulation, explaining the side effect of decreased libido with selective serotonin reuptake inhibitors (SSRIs) used to treat depres- sion. Administration of L-dopa increases libido. Noradrenergic receptors in the brain exert an inhibitory effect on penile erection.

Question 29

Q

The peak reduction in intracranial pressure (ICP) after administration of manni-
tol occurs in about
A. 4 hours.
B. 2 hours.
C. 1 hour.
D. 30 minutes.
E. 15 minutes

Answer

A

A. 4 hours.
B. 2 hours.
C. 1 hour.
D. 30 minutes.
E. 15 minutes

The peak reduction in intracranial pressure (ICP) occurs in about 15 minutes after administration of mannitol. The duration of action of mannitol is about 4 hours due to the rapid renal elimination of the drug. When mannitol is used with furosemide, the combined effect on ICP reduction is greater than if either were used alone.

Question 30

Q

The borders of the paramedial triangle are cranial nerves
A. I and II.
B. II and III.
C. III and IV
D. IV and V.
E. None of the above

Answer

A

A. I and II.
B. II and III.
C. III and IV
D. IV and V.
E. None of the above

The paramedial triangle (also known as the supratrochlear triangle) is defined medially by the medial border of the oculomotor nerve and laterally by the lateral border of the trochlear nerve.

Question 31

Q

The Tensilon test
A. is not sensitive but very specifi c for myasthenia gravis (MG).
B. is not particularly useful in ocular MG.
C. when negative, rules out the diagnosis of MG.
D. shows no correlation with subsequent response to pyridostigmine
E. is not aff ected by the quantity of acetylcholine receptors.

Answer

A

The Tensilon test
A. is not sensitive but very specifi c for myasthenia gravis (MG).
B. is not particularly useful in ocular MG.
C. when negative, rules out the diagnosis of MG.
D. shows no correlation with subsequent response to pyridostigmine
E. is not aff ected by the quantity of acetylcholine receptors.

The Tensilon test is sensitive in diagnosing a defect in neuromuscular trans- mission but is not specific for myasthenia gravis (MG). The Tensilon test is especially useful in ocular MG, when other diagnostic tests may be negative. Depending on the mechanism of acetylcholine receptor (AchR) antibodies, there may be insufficient numbers of AchRs available so that a negative Tensi- lon test does not negate the diagnosis of MG. There is no correlation between the results of the Tensilon test and the subsequent response to pyridostigmine.

Question 32

Q

In posterior interosseous syndrome, there is a fi ngerdrop but no wristdrop because of sparing of the
A. extensor carpi radialis longus.
B. extensor carpi radialis brevis.
C. extensor digitorum.
D. extensor carpi ulnaris
E. brachioradialis.

Answer

A

D. extensor carpi ulnaris

The posterior interosseous nerve (C7, C8) is a branch of the radial nerve. The
posterior interosseous nerve innervates the extensor digitorum, extensor
digiti minimi, and extensor carpi ulnaris. The extensor carpi ulnaris extends
the hand at the wrist joint. This muscle is spared in posterior interosseous
syndrome

The posterior interosseous nerve (C7, C8) is a branch of the radial nerve. The posterior interosseous nerve innervates the extensor digitorum, extensor digiti minimi, and extensor carpi ulnaris. The extensor carpi ulnaris extends the hand at the wrist joint. This muscle is spared in posterior interosseous syndrome.

Question 33

Q

What is the Spetzler–Martin grade of this arteriovenous malformation (AVM)
found in a 30-year-old asymptomatic healthy patient?
A. 1
B. 2
C. 3
D. 4
E. 5

Answer

A

B. 2

The magnetic resonance angiography scan (MRA) represents the findings of a left anterior frontal arteriovenous malformation (AVM) of which the nidus measures between 3 and 6 cm, which adds two points in the Spetzler–Martin grading system. It is located in noneloquent brain and has superficial drainage; therefore it is a grade 2 Spetzler–Martin AVM.

Question 34

Q

Interruption of the inferior geniculocalcarine fibers results in which of the following?
A. Ipsilateral superior quadrantanopia
B. Contralateral superior quadrantanopia
C. Ipsilateral inferior quadrantanopia
D. Contralateral inferior quadrantanopia
E. None of the above

Answer

A

B. Contralateral superior quadrantanopia

Interruption of the inferior geniculocalcarine fibers in the temporal lobe pro- duces a “pie in the sky” deficit (contralateral superior quadrantanopia).

Question 35

Q

Which of the following may be seen with ocular myoclonus?
A. Vertical oscillation of the eyes occurring with movements of the palate
B. Hypertrophy of the inferior olivary nucleus
C. Prior lesions of the central tegmental tract
D. All of the above
E. None of the above

Answer

A

D. All of the above

Ocular myoclonus is a pendular vertical oscillation of the eyes, usually of large amplitude and often occurring with movements of the palate. It can devel- op months to years after bilateral destructive lesions of the central tegmental tract and is often accompanied by bilateral horizontal gaze palsies and is asso- ciated with hypertrophy of the inferior olivary nucleus.

Question 36

Q

All of the following characterize Acute respiratory distress syndrome (ARDS) EXCEPT :
A. Late hypoxemia
B. Diffuse infiltrate
C. Leaky capillaries
D. Association with sepsis and trauma
E. Protein content of fluid greater than with pulmonary edema

Answer

A

A. Late hypoxemia
B. Diffuse infiltrate
C. Leaky capillaries
D. Association with sepsis and trauma
E. Protein content of fluid greater than with pulmonary edema

Early hypoxemia characterizes ARDS.

Question 37

Q

In a healing wound, maximum collagen deposition occurs at
A. 2 weeks.
B. 4 weeks.
C. 6 weeks.
D. 8 weeks.
E. 10 weeks.

Answer

A

A. 2 weeks.
B. 4 weeks.
C. 6 weeks.
D. 8 weeks.
E. 10 weeks.

Maximum collagen deposition occurs at 42 days (about 6 weeks). Tensile strength keeps on increasing until 2 years.

Question 38

Q

All of the following are true regarding the condition depicted by this histopathology EXCEPT:
A. It is histologically characterized by a biphasic pattern.
B. Rosenthal fibers are a prerequisite for this diagnosis.
C. It may mimic oligodendroglioma.
D. It is a CNS neoplasm seen with neurofibromatosis type 1.
E. Recurrence is usually a reformation of the cyst rather than the solid tumor.

Answer

A

A. It is histologically characterized by a biphasic pattern.
B. Rosenthal fibers are a prerequisite for this diagnosis.
C. It may mimic oligodendroglioma.
D. It is a CNS neoplasm seen with neurofibromatosis type 1.
E. Recurrence is usually a reformation of the cyst rather than the solid tumor

Rosenthal fibers are by no means a requisite feature of pilocytic astrocytoma. Rosenthal fibers are composed of alpha B cystallin and are surrounded by in- termediate filaments.

Question 39

Q

Barbiturates presumably act by which of the following mechanisms?
A. Inverse steal phenomenon
B. Decrease CMR
C. Decrease oxygen consumption
D. Scavenge free radicals
E. All of the above

Answer

A

E. All of the above

Barbiturates are also thought to stabilize lysosomes, suppress the formation of edema, and reduce intracellular accumulation of calcium. The inverse steal phenomenon involves barbiturate-induced vasoconstriction resulting in shunting of blood from normal brain to relatively ischemic areas.

Question 40

Q

Parkinson’s (infratrochlear) triangle is defi ned by cranial nerves
A. II and III.
B. III and IV.
C. IV and V1
D. V1 and V2.
E. V2 and V3

Answer

A

A. II and III.
B. III and IV.
C. IV and V1.
D. V1 and V2.
E. V2 and V3

Parkinson’s triangle is also known as the infratrochlear triangle.

Question 41

Q

Which of the following is true of myasthenia gravis?
A. The majority of acetylcholine receptor antibodies are of the M subtype.
B. Cyclosporine is used as a fi rst-line treatment.
C. Corticosteroids may reduce the risk of secondary generalization in the ocular form
D. Pathological abnormalities of the thymus are found in less than 5% of patients.
E. Weakness confined to the ocular muscles beyond 3 years is associated with poor prognosis.

Answer

A

A. The majority of acetylcholine receptor antibodies are of the M subtype.
B. Cyclosporine is used as a fi rst-line treatment.
C. Corticosteroids may reduce the risk of secondary generalization in the ocular form
D. Pathological abnormalities of the thymus are found in less than 5% of patients.
E. Weakness confined to the ocular muscles beyond 3 years is associated with poor prognosis.

The majority of acetylcholine receptor (AchR) antibodies are immunoglobulin G (IgG). Cyclosporine should be used once first-line treatments have failed. Pathological abnormalities of the thymus occur in up to 80% of patients. Weak- ness confined to the ocular muscles for over 3 years suggests good prognosis.

Question 42

Q

The border of the foramen lacerum is formed by the
A. sphenoid bone.
B. temporal bone.
C. sphenoid and temporal bones.
D. sphenoid, temporal, and occipital bones
E. occipital bone.

Answer

A

D. sphenoid, temporal, and occipital bones

Question 43

Q

Absence of infl ammation is typical of the following diseases EXCEPT:
A. Neuropathy from diphtheria
B. Creutzfeldt–Jakob disease
C. Paraneoplastic necrotizing myelopathy
D. Central pontine myelinolysis
E. Tolosa–Hunt syndrome

Answer

A

A. Neuropathy from diphtheria
B. Creutzfeldt–Jakob disease
C. Paraneoplastic necrotizing myelopathy
D. Central pontine myelinolysis
E. Tolosa–Hunt syndrome

Tolosa–Huntsyndromeischaracterizedbyocularandretro-orbitalpain,ocu- lar motor paralysis (with papillary sparing), and possibly sensory loss over the forehead with granulomatous inflammation of the superior orbital fissure or the lateral wall of the cavernous sinus. The other conditions described lack an inflammatory response.

Question 44

Q

Wernicke’s area is BEST described as including
A. area 39.
B. supramarginal, area 40, and posterior one-third of the superior temporal
gyri.
C. angular and posterior one-third of the superior temporal gyri.
D. areas 39 and 40.
E. supramarginal and posterior one-third of the superior temporal gyri

Answer

A

B.

The most accurate description of Wernicke’s area is that it includes the supramarginal (39), angular (40), and posterior one-third of the superior temporal gyri.

Tolosa–Hunt syndrome is characterized by ocular and retro-orbital pain, ocular motor paralysis (with papillary sparing), and possibly sensory loss over the forehead with granulomatous inflammation of the superior orbital fissure or the lateral wall of the cavernous sinus. The other conditions described lack an inflammatory response.

Question 45

Q

Anti-pause cell antibody may be seen with childhood infections or paraneoplastic syndrome in adults. Immune-mediated defects in pause cell function most likely result in
A. opsoclonus.
B. square wave jerks.
C. downbeat nystagmus.
D. upbeat nystagmus.
E. None of the above

Answer

A

A. opsoclonus.

Bursts of back-to-back saccades seen in opsoclonus and ocular fl utter may be
attributable to a disorder of pause cell modulation of burst cell function.

Bursts of back-to-back saccades seen in opsoclonus and ocular flutter may be attributable to a disorder of pause cell modulation of burst cell function.

Question 46

Q

The origin of axons that mediate the swallowing reflex is the…
A. solitary nucleus.
B. dorsal motor nucleus of X.
C. nucleus ambiguus
D. All of the above
E. None of the above

Answer

A

C. nucleus ambiguus

Question 47

Q

Match these MRI scan findings with the following comments:
Hypertension
A. Scan 1
B. Scan 2
C. Both scans 1 and 2
D. Neither scan 1 nor scan 2

Answer

A

A. Scan 1

Scan 1 shows a glomus tympanicum tumor, which may be associated with
catecholamine release causing hypertension, or serotonin and kallikrein release causing bronchoconstriction, abdominal pain, and explosive diarrhea. Glomus tympanicum tumors may also release histamine and
bradykinins during surgery causing hypotension and bronchoconstriction.

Scan 1 shows a glomus tympanicum tumor, which may be associated with catecholamine release causing hypertension, or serotonin and kallikrein release causing bronchoconstriction, abdominal pain, and explosive diarrhea. Glomus tympanicum tumors may also release histamine and bradykinins during surgery causing hypotension and bronchoconstriction

Question 48

Q

Match these MRI scan findings with the following comments:
Early facial nerve involvement
A. Scan 1
B. Scan 2
C. Both scans 1 and 2
D. Neither scan 1 nor scan 2

Answer

A

B. Scan 2
Scan 2 shows a meningioma of the cerebellopontine angle (CPA),
which usually presents initially with facial nerve involvement. Acoustic
schwannomas present initially with hearing loss and tinnitus

Scan 2 shows a meningioma of the cerebellopontine angle (CPA), which usually presents initially with facial nerve involvement. Acoustic schwannomas present initially with hearing loss and tinnitus.

Question 49

Q

Match these MRI scan findings with the following comments:
Hypotension and bronchoconstriction during resection
A. Scan 1
B. Scan 2
C. Both scans 1 and 2
D. Neither scan 1 nor scan 2

Answer

A

A. Scan 1
B. Scan 2
C. Both scans 1 and 2
D. Neither scan 1 nor scan 2

Scan 1 shows a glomus tympanicum tumor, which may be associated with catecholamine release causing hypertension, or serotonin and kallikrein release causing bronchoconstriction, abdominal pain, and explosive diarrhea. Glomus tympanicum tumors may also release histamine and bradykinins during surgery causing hypotension and bronchoconstriction

Question 50

Q

Match these MRI scan findings with the following comments:
Explosive diarrhea
A. Scan 1
B. Scan 2
C. Both scans 1 and 2
D. Neither scan 1 nor scan 2

Answer

A

A. Scan 1
B. Scan 2
C. Both scans 1 and 2
D. Neither scan 1 nor scan 2

Scan 1 shows a glomus tympanicum tumor, which may be associated with catecholamine release causing hypertension, or serotonin and kallikrein release causing bronchoconstriction, abdominal pain, and explosive diarrhea. Glomus tympanicum tumors may also release histamine and bradykinins during surgery causing hypotension and bronchoconstriction

Question 51

Q

Match these MRI scan findings with the following comments:
Early hearing loss and tinnitus
A. Scan 1
B. Scan 2
C. Both scans 1 and 2
D. Neither scan 1 nor scan 2

Answer

A

D. Neither scan 1 nor scan 2

Question 52

Q

Laboratory manifestations of disseminated intravascular coagulation (DIC) include all of the following EXCEPT:
A. Increased fibrinogen level
B. Prolonged PT
C. Prolonged PTT
D. Thrombocytopenia
E. Fragmented RBCs

Answer

A

A. Increased fibrinogen level
B. Prolonged PT
C. Prolonged PTT
D. Thrombocytopenia
E. Fragmented RBCs

Disseminated intravascular coagulation (DIC) is most frequently associated with obstetric catastrophes, metastatic malignancy, massive trauma, and bac- terial sepsis. The neurosurgeon should be aware that DIC can occur when there is major cerebral tissue injury. The decrease in fibrinogen most closely corre- lates with increased bleeding. Treatment is by removing the causative agent, heparin, cryoprecipitate, platelets, and whole blood.

Question 53

Q

The mastoid air cells are innervated by
A. V1.
B. V2.
C. V3.
D. IX.
E. X.

Answer

A

C. V3

The mastoid air cells and the posterior middle fossa are innervated by V3. The supratentorial compartment is innervated by V1 and V2. The infratentorial compartment is innervated by IX, X, and C1–C3 posterior roots.

Question 54

Q

Which of the following statements is most accurate regarding the band of Gennari?
A. It divides the third layer of the cortex of areas 17 and 18.
B. It divides the third layer of the cortex of area 17.
C. It divides the fourth layer of the cortex of areas 17 and 18.
D. It divides the fourth layer of the cortex of area 17.
E. It divides the fourth layer of the cortex of areas 17, 18, and 19.

Answer

A

A. It divides the third layer of the cortex of areas 17 and 18.
B. It divides the third layer of the cortex of area 17.
C. It divides the fourth layer of the cortex of areas 17 and 18.
D. It divides the fourth layer of the cortex of area 17.
E. It divides the fourth layer of the cortex of areas 17, 18, and 19.

The band of Gennari divides the fourth layer of cortex into two granular layers with a thick myelin layer. The band is located only in area 17 (primary visual cortex, also known as V1). When Gennari described this in 1782, he had no idea that this or any other region of the visual cortex might be concerned with vision.

Question 55

Q

The following are prenuclear structures for vertical gaze EXCEPT:
A. Nucleus of Darkshevich
B. Posterior commissure
C. Interstitial nucleus of Caja
D. Rostral interstitial nucleus of the medial longitudinal fasciculus (MLF)
E. Nucleus prepositus hypoglossi**

Answer

A

E. Nucleus prepositus hypoglossi

The neural integrator for horizontal eye movement sislocated in the nucleus prepositus hypoglossi (NPH) at the pontomedullary junction.

Question 56

Q

Which of the following neurons or nerve cell processes is/are particularly involved with new, novel movements?
A. Mossy fibers
B. Betz cell
C. Climbing fibers
D. All of the above
E. None of the above**

Answer

A

C. Climbing fibers

Climbing fiber input is most active at times when the subject is performing new complex movements. The climbing fiber input can modify the synapse between the parallel fiber (from the granule cell) and the Purkinje cell.

Question 57

Q

Which of the following disease states is characterized by high trophic hormone and low target hormone?
A. Cushing’s disease
B. Graves’s disease
C. Adrenal tumors
D. Addison’s disease
E. None of the above**

Answer

A

A. Cushing’s disease
B. Graves’s disease
C. Adrenal tumors
D. Addison’s disease
E. None of the above

The combination of high trophic hormone and low target hormone indicates target gland failure.

Question 58

Q

Which of the following intrinsic muscles of the thumb does NOT insert on the proximal phalanx?
A. Adductor pollicis
B. Abductor pollicis brevis
C. Flexor pollicis brevis
D. Opponens pollicis
E. Extensor pollicis brevis**

Answer

A

A. Adductor pollicis
B. Abductor pollicis brevis
C. Flexor pollicis brevis
D. Opponens pollicis
E. Extensor pollicis brevis

The opponens pollicis inserts on the first metacarpal bone.

Question 59

Q

Which of the following statements is FALSE with regard to the scan shown here?
A. The fi rst symptom in 90% of patients is unilateral hearing loss.
B. Headaches, clumsy gait, and mental confusion may occur.
C. The seventh cranial nerve is frequently involved preoperatively
D. Essentially everyone who has been treated for an acoustic neuroma experiences difficulty with balance and/or dizziness to some degree.
E. Sporadic defects in tumor suppressor genes may give rise to these tumors.

Answer

A

C. The seventh cranial nerve is frequently involved preoperatively

The MRI with contrast demonstrates a left cerebellopontine angle lesion most consistent with a vestibular schwannoma. Most patients have involvement of the eighth cranial nerve initially. They may also more commonly present with decreased facial sensation or numbness with involvement of the trigeminal nerve; however, facial nerve involvement with a tumor of the size shown is relatively uncommon.

Question 60

Q

Match these brachial plexus structures with the appropriate letter in the diagram:
Long thoracic nerve
A. A
B. B
C. C
D. D
E. E

Question 61

Q

Match these brachial plexus structures with the appropriate letter in the diagram:
Long thoracic nerve
A. A
B. B
C.C
D. D
E. E

Question 62

Q

Match these brachial plexus structures with the appropriate letter in the diagram:
Medial antebrachial cutaneous nerve
A. A
B. B
C. C
D. D
E. E

Question 63

Q

Match these brachial plexus structures with the appropriate letter in the diagram:
Suprascapular nerve
A. A
B. B
C. C
D. D
E. E**

Question 64

Q

Match these brachial plexus structures with the appropriate letter in the diagram:
Median pectoral nerve
A. A
B. B
C. C
D. D
E. E

Answer 60

A

C. Vergence

The medial longitudinal fasciculus (MLF) is responsible for the binocular coordination of all categories of horizontal, vertical, and oblique eye movements with the exception of vergence movements. Upbeating nystagmus on upgaze is a feature of MLF lesions.

The medial longitudinal fasciculus (MLF) is responsible for the binocular co- ordination of all categories of horizontal, vertical, and oblique eye movements with the exception of vergence movements. Upbeating nystagmus on upgaze is a feature of MLF lesions.

Answer 61

A

C. Severity of mental retardation

Both Apert’s and Crouzon’s syndromes are autosomal dominant (both may also be sporadic). Both are associated with bilateral coronal synostosis. Patients with Apert’s syndrome manifest more severe mental retardation than patients with Crouzon’s syndrome.

Answer 62

A

A. prolactin.
B. ACTH.
C. GH.
D. TSH.
E. All of the above

In addition to stimulating the synthesis and secretion of thyroid stimulating hormone (TSH), thyrotropin-releasing hormone (TRH) is a potent secretagogue for prolactin, and to a lesser extent adrenocorticotropic hormone (ACTH), and growth hormone (GH).

Answer 63

A

A. Radial only
B. Radial and median
C. Radial, median, and ulnar
D. Radial, median, and axillary
E. Musculocutaneous, median, and ulnar

The metacarpophalangeal joint of the ring finger is flexed by the lumbrical, pal- mar, and dorsal interosseous muscles, which are innervated by the ulnar nerve. The joint is extended by the extensor digitorum, which is innervated by the ra- dial nerve. The median nerve is mainly involved with flexion of the ring finger.

Answer 64

A

A. Survivin
B. MMP-9
C. EGFR
D. MDM2
E. Fas (APO-1/CD95)

Profileexpression: Survivin—83%
MMP-9—69%
EGFR—63%
MDM2—31%
Fas (APO-1/CD95)—100%

Answer 65

A

A. Lateral triangle
B. Paramedial triangle
C. Glasscock’s triangle
D. Kawase’s triangle
E. Parkinson’s triangle

Answer 66

A

E. Levels are increased after nonepileptic seizures.

Serum concentration of prolactin (PRL) is increased after tonicoclonic seizure
activity but is not aff ected by nonepileptic seizures.

Serum concentration of prolactin (PRL) is increased after tonico clonic seizure activity but is not affected by nonepileptic seizures.

Answer 67

A

A. Organum vasculosum of the lamina terminalis
B. Median eminence of the tuber cinereum
C. Subcommissural organ
D. Subfornical organ
E. Area postrema

The subfornical organ is located on the inferior surface of the fornix at the level of the foramen of Monro.

Answer 68

A

A. It is a branch from the posterior division of the spinal nerve proximal to the dorsal root ganglion.
B. It may enter the intervertebral foramen.
C. It supplies most of the innervation to the posterior aspect of the disk.
D. It may have a proprioceptive and/or nociceptive function.
E. It has been shown to consist of two roots at cervical levels

The sinuvertebral nerve arises just distal to the dorsal root ganglion. The pos- terior disk receives its innervation from the sinuvertebral nerves. The anterior disk receives its innervation from the gray rami communicans.

Answer 69

A

A. It is caused by a lesion of the arcuate fasciculus.
B. There is fluent paraphasic speech with intact repetition.
C. It may be caused by occlusion of a middle cerebral artery(MCA) posterior temporal branch.
D. Patients may mimic Wernicke’s disease, but are able to understand.
E. Patients are aware of the problem

Repetition is impaired in conduction aphasia.

Answer 70

A

A. It arises from the cavernous internal carotid artery.
B. It measures ~6–8 mm.
C. It usually presents pituitary dysfunction.
D. All of the above statements are true.
E. None of the above statements are true

The usual diameter of the internal cerebral artery at the clinoid area is about 8 mm. This aneurysm is slightly smaller than the artery’s diameter.

Answer 71

A

A. Vertebral blood flow
B. Carotid blood flow
C. Cervical stenosis
D. Thoracic stenosis
E. Lumbar stenosis

TheTorg Pavlov ratio is a measure of cervical spinal stenosis and is the ratio of spinal canal to vertebral body. A normal cervical spinal canal will have a ratio of about 1.0. A stenotic cervical canal has a ratio of <0.8

Answer 72

A

A. Primary glioblastoma has an incidence that is about 10 times higher than secondary glioblastoma.
B. The mean age at presentation in primary glioblastoma is much younger (45 years) than in secondary glioblastoma (62 years)
C. Primary glioblastoma is more common in males when compared with secondary glioblastoma.
D. The median survival at presentation is longer in secondary glioblastoma as compared with primary glioblastoma.
E. Loss of heterozygosity on 10p or 10q is one of the most common genetic mutations in primary glioblastoma.

Primary glioblastoma has an incidence that is about 10 times higher than sec- ondary glioblastoma. The mean age at presentation in secondary glioblastoma is much younger (45 years) than in primary glioblastoma (62 years). Primary glioblastoma is more common in males when compared to secondary glioblas- toma. The median survival at presentation is longer in secondary glioblastoma as compared to primary glioblastoma. Loss of heterozygosity on 10p or 10q is one of the most common genetic mutations in primary glioblastoma.

Answer 73

A

A. dorsal root ganglia only.
B. anterior horn only.
C. sympathetic chain ganglia and dorsal root ganglia.
D. lateral horn and sympathetic chain ganglia.
E. None of the above

The medial brachial cutaneous nerve (from the medial cord) contains sensory fibers that have cell bodies in the dorsal root ganglia. It also contains sym- pathetic postganglionic fibers that have cell bodies in the sympathetic chain ganglia.

Answer 74

A

A. inhibitory pathway of the hippocampus.
B. excitatory pathway of the hippocampus.
C. inhibitory pathway of the hypothalamus.
D. excitatory pathway of the hypothalamus.
E. None of the above

The perforant path is the main excitatory pathway to the hippocampus. When perforant path fibers are stimulated, histological changes develop in the py- ramidal nerve cells of CA1 and CA3.

Answer 75

A

A. Parkinson’s triangle
B. Kawase’s triangle
C. Glasscock’s triangle
D. Inferior medial triangle
E. Paramedial triangle

Answer 76

A

A. cluster.
B. tension.
C. migraine.
D. postconcussive.
E. due to temporal arteritis

Up to 80% of the population will experience a tension headache in their life- time. Amitriptyline is the most effective medication used to prevent tension headaches.

Answer 77

A

A. Cerebellomedullary
B. Interpeduncular
C. Ambient
D. Chiasmatic
E. Pontine

The ambient cistern contains the trochlear nerve.

Answer 78

A

A. Anterior scalene
B. Anterior and medial
C. Medial and posterior
D. Anterior and posterior
E. Anterior, medial, and posterior

The anterior and medial scalene muscles insert onto the first rib, and the sub-
clavian artery, subclavian vein, and brachial plexus pass between them.

Answer 79

A

A. pure word blindness.
B. pure word deafness
C. mutism.
D. anomic aphasia.
E. global aphasia

Pure word blindness is characterized by alexia without agraphia. The patient is unable to read but is able to understand speech, write, and speak. It is caused by a lesion of the left geniculocalcarine tract and the corpus callosum.

Answer 80

A

A. Improvement in IQ is often seen postoperatively.
B. Behavior is improved after surgery.
C. It is not necessary to preserve the septum pellucidum
D. The foramen of Monro is often plugged with a piece of temporalis muscle.
E. Patients are usually uncommunicative for about a week after surgery.

Preventing seepage of blood into the ventricular system during a hemispherec- tomy is accomplished by obstructing the foramen of Monro and maintaining the integrity of the septum pellucidum.

Answer 81

A

A. horizontal fi bers have a limited functional role
B. vertical fi bers have a limited functional role.
C. the pia has a limited functional role.
D. All of the above
E. None of the above

Experiments in functional physiology defined a limited role of the horizontal fibers and reinforced the anatomical principles of vertical columnar organiza- tion in the cortex. This functional columnar organization of cortical architec- ture is the key principle in multiple subpial transection.

Answer 82

A

A. headache.
B. vomiting.
C. visual fi eld disturbance.
D. sexual precocity
E. seizures.

Sexual precocity is often the presenting symptom of hypothalamic hamarto- mas. Hamartomas may also cause gelastic (laughing) seizures.

Answer 83

A

A. It is found in superfi cial brain regions.
B. It shows intracellular accumulation of lipids.
C. It corresponds to WHO grade II.
D. It carries a dismal prognosis
E. It presents in patients with a long history of seizures.

Pleomorphic xanthoastrocytoma (PXA) is an astrocytic neoplasm with a rela- tively favorable prognosis.

Answer 84

A

B. excitatory input from CA3.
A. excitatory input from CA1.
B. excitatory input from CA3.
C. inhibitory input from CA1.
D. inhibitory input from CA3.
E. None of the above

ExcitatoryinputfromCA3toCA1pyramidalcellsiscarriedbySchaffercollat- erals. These collaterals spare the CA2 region.

Answer 85

A

A. Gastrocnemius
B. Tibialis anterior
C. Extensor hallucis longus
D. Iliopsoas
E. None of the above

The MRI scan of the lumbar spine demonstrates a far lateral foraminal disk herniation at L4–L5 on the left side. Most likely, the L4 nerve root will be in- volved and the patient will present with weakness of the tibialis anterior and decreased sensation along an L4 distribution in the left lower extremity.

Answer 86

A

A. Midline laminectomy approach
B. Paramedian partial facetectomy approach
C. Transforaminal lumbar interbody fusion
D. Posterior lumbar interbody fusion
E. A and C

Althoughamidlinelaminotomyorlaminectomymaybeemployedfordecom- pression and removal of the disk it is often more effective to approach the disk via a direct approach that is paramedian with a partial facetectomy in order to remove the foraminal and extraforaminal portions.

Answer 87

A

A. Pyramids
B. Medial lemniscus
C. Fibers of cranial nerve XII
D. Gracile and cuneate nuclei
E. Anterior two-thirds of the spinal cord

The gracile and cuneate fasciculi are supplied by the posterior spinal arteries. The paired posterior spinal arteries (arising from either the posterior inferior cerebellar artery (PICA) or vertebral artery) supply the posterior one-third of the spinal cord.

Answer 88

A

C. Adson’s test

Adson’s test is used in the examination of thoracic outlet syndrome. In this
example the examiner is checking to see if the radial pulse is obliterated. Compression of nerves causes wasting of muscles supplied by the lower trunk of
the brachial plexus

Adson’s test is used in the examination of thoracic outlet syndrome. In this example the examiner is checking to see if the radial pulse is obliterated. Com- pression of nerves causes wasting of muscles supplied by the lower trunk of the brachial plexus.

Answer 89

A

E. Genu

The corticobulbar tract is located in the genu of the internal capsule

The corticobulbar tract is located in the genu of the internal capsule.

Answer 90

A

D. Medulla

The medial forebrain bundle traverses the entire lateral hypothalamic area and interconnects the septal area and nuclei, the hypothalamus, and the midbrain tegmentum. The medulla is connected with the hypothalamus via the dorsal longitudinal fasciculus, which projects to the parasympathetic nuclei of the brainstem.

Answer 91

A

D. All of the above

It is postulated that the closure of the lambdoid sutures, common in Crouzon’s
syndrome, results in cerebellar tonsillar herniation.

It is postulated that the closure of the lambdoid sutures, common in Crouzon’s syndrome, results in cerebellar tonsillar herniation.

Answer 92

A

A. lateral hypothalamus.
B. anterior hypothalamus.
C. posterior hypothalamus.
D. ventromedial hypothalamus.
E. suprachiasmatic hypothalamus

The most severe forms of hypothalamic cachexia are seen in lesions of the lat- eral hypothalamus.

Answer 93

A

A. temporal cortex.
B. cingulate cortex.
C. prefrontal cortex.
D. posterior parietal cortex.
E. anterior parietal cortex.

Lesions of the prefrontal cortex result in a failure to discriminate odors. The prefrontal cortex receives projections from the pyriform cortex. There is also a projection from the pyriform cortex to the dorsomedial thalamus to the pre- frontal cortex.

Answer 94

A

A. Phenylalanine and tyrosine
B. Phenylalanine and tryptophan
C. Tyrosine and tryptophan
D. Arginine and tyrosine
E. Phenylalanine and arginine

The amino acids phenylalanine and tyrosine are precursors for catecholamines (dopamine, norepinephrine, epinephrine).

Answer 95

A

A. Melanoma
B. Choriocarcinoma
C. Breast carcinoma
D. Renal cell carcinoma
E. Choroid plexus papilloma

Renal cell carcinoma has a predilection to the ventricular system.

Answer 96

A

A. loss of heterozygosity 10q.
B. TP53 mutation.
C. EGFR amplifi cation.
D. p16INK4a deletion.
E. PTEN mutations (25%).

The majority of cases of glioblastomas are primary that develop without clinical or histological evidence of a less malignant precursor lesion. They occur primarily in the elderly and typically present genetically with loss of heterozygosity 10q, EGFR amplification, p16INK4a deletion, and PTEN muta- tions. Secondary glioblastomas occur through progression from low-grade diffuse astrocytoma or anaplastic astrocytoma and tend to present in young- er patients. TP53 mutations are the most frequent in the pathways to these tumors being often present in precursor low-grade astrocytomas.

Answer 97

A

A. internal cerebral vein and basal vein.
B. inferior sagittal sinus and vein of Galen
C. basal vein and great cerebral vein.
D. inferior sagittal vein and basal vein.
E. precentral cerebellar vein and internal cerebral vein

The straight sinus is formed by the great cerebral vein (of Galen) and the
inferior sagittal sinus.

Answer 98

A

A. ocular fl utter.
B. ocular dysmetria.
C. ocular bobbing.
D. oscillopsia.
E. opsoclonus

Oscillopsia is a condition where objects seem to wiggle; it sometimes accom- panies downbeat nystagmus.

Answer 99

A

A. Parasympathetic preganglionic
B. Parasympathetic postganglionic
C. Sympathetic postganglionic
D. All of the above
E. None of the above

Atropine blocks only muscarinic receptors, thus only preganglionic synapses are affected.

Answer 100

A

A. vitamin B1

Wernicke’s encephalopathy is due to defi ciency of thiamine (B1).

Wernicke’s encephalopathy is due to deficiency of thiamine (B1).

Answer 101

A

D. All of the above

Gustatory fi bers of the solitary nucleus terminate in the VPM. Fibers carrying
thoracic information travel via solitary tract and terminate in the parabrachial
nucleus and hypothalamus

Gustatory fibers of the solitary nucleus terminate in the VPM. Fibers carrying thoracic information travel via solitary tract and terminate in the parabrachial nucleus and hypothalamus.

Answer 102

A

B. the presence of mitotic activity.

In contrast to diffuse astrocytomas, anaplastic astrocytomas typically display
mitotic activity.

In contrast to diffuse astrocytomas, anaplastic astrocytomas typically display mitotic activity.

Answer 103

A

D. cavernous hemangioma

The typical site for a cavernous hemangioma of the orbit is in the intraconal
space lateral to the optic nerve

The typical site for a cavernous hemangioma of the orbit is in the intraconal space lateral to the optic nerve.

Answer 104

A

D. Exposure to highly active antiretroviral therapy (HAART)

HIV-infected individuals have an increased risk of cerebrovascular incidents
associated with intravenous drug abuse, low CD4 cell count, and exposure to
abacavir, but not with HAART. A CD4 cell count ≤ 200 cells/mL prior the start
of HAART increased the risk of cerebrovascular events.

HIV-infected individuals have an increased risk of cerebrovascular incidents associated with intravenous drug abuse, low CD4 cell count, and exposure to abacavir, but not with HAART. A CD4 cell count ≤ 200 cells/mL prior the start of HAART increased the risk of cerebrovascular events.

Answer 105

A

E. periventricula

Arteries from the ependymal surface feed the arteriovenous malformation
(AVM)

Arteries from the ependymal surface feed the arteriovenous malformation (AVM).

Answer 106

A

A. dopamine beta -hydroxylase.
Under conditions of neuronal activation, dopamine beta-hydroxylase is the
rate-limiting step. However, under basal conditions tyrosine hydroxylase is
the rate-limiting step

Under conditions of neuronal activation, dopamine beta-hydroxylase is the rate-limiting step. However, under basal conditions tyrosine hydroxylase is the rate-limiting step.

Answer 107

A

B. Septal and terminal

The venous angle is a landmark of the foramen of Monro. It is formed by the
union of the septal vein and the terminal (also called thalamostriate) vein

The venous angle is a landmark of the foramen of Monro. It is formed by the union of the septal vein and the terminal (also called thalamostriate) vein.

Answer 108

A

E. All of the above
Ocular bobbing is a rapid downward movement of the eyes with a slow return to midposition and has many causes.

Ocular bobbing is a rapid downward movement of the eyes with a slow re- turn to midposition and has many causes.

Answer 109

A

E. osteoid osteoma

This CT scan reveals dense sclerosis around a lytic lesion with a central
calcifi ed nodule in the lumbar neural arch consistent with osteoid osteoma.

This CT scan reveals dense sclerosis around a lytic lesion with a central calcified nodule in the lumbar neural arch consistent with osteoid osteoma.

Answer 110

A

C. the arcuate nuclei

The striae medullares (rhombencephali) arise from the arcuate nuclei of the
medulla and are seen on the floor of the rhomboid fossa. These fibers divide
the rhomboid fossa into a rostral pontine half and a caudal medullary half.
The stria medullaris (thalami) contains septohabenular fi bers. The stria terminalis is a semicircular fi ber bundle extending from the amygdala to the hypothalamus and septal area

The striae medullares (rhombencephali) arise from the arcuate nuclei of the medulla and are seen on the floor of the rhomboid fossa. These fibers divide the rhomboid fossa into a rostral pontine half and a caudal medullary half. The stria medullaris (thalami) contains septohabenular fibers. The stria ter- minalis is a semicircular fiber bundle extending from the amygdala to the hypothalamus and septal area.

Answer 111

A

C. diffusion.

No blood vessels penetrate the intervertebral disk. Delivery of nutrients is entirely dependent on diff usion

No blood vessels penetrate the intervertebral disk. Delivery of nutrients is entirely dependent on diffusion.

Answer 112

A

D. Stimulation of it inhibits acoustic fi ber responses to
auditory stimuli.

The olivocochlear bundle arises from the region of the superior olivary nucleus and projects contralaterally back to the hair cells of the cochlea. Stimulation of this bundle results in nhibition or reduction of responses of auditory signals by auditory nerve fibers.

The olivocochlear bundle arises from the region of the superior olivary nucleus and projects contralaterally back to the hair cells of the cochlea. Stimulation of this bundle results in inhibition or reduction of responses of auditory signals by auditory nerve fibers.

Answer 113

A

B. Pleomorphic adenoma of the lacrimal gland

Pleomorphic adenomas of the lacrimal gland should be removed with a cuff
of normal tissue to reduce the risk of tumor seeding and recurrence. An incisional biopsy should not be performed on this type of tumor.

Pleomorphic adenomas of the lacrimal gland should be removed with a cuff of normal tissue to reduce the risk of tumor seeding and recurrence. An inci- sional biopsy should not be performed on this type of tumor.

Answer 114

A

C. Palatine and sphenoid

Answer 115

A

C. Broca’s area.

Answer 116

A

C. The fluid collection is typically not lined by ependymal cells.

Hydromyelia has ependymal lining. It can be associated with both hydrocephalus and Chiari but can also be postmeningitic and associated with
tumors. It can be either communicating with the fourth ventricle or just isolated and noncommunicating. Syrinxes on the other hand lack any ependymal lining.

Hydromyelia has ependymal lining. It can be associated with both hydro- cephalus and Chiari but can also be postmeningitic and associated with tumors. It can be either communicating with the fourth ventricle or just iso- lated and noncommunicating. Syrinxes on the other hand lack any ependy- mal lining.

Answer 117

A

B. Superior cerebellar artery

The superior cerebellar artery supplies the superior surface of the cerebellum and the cerebellar nuclei

The superior cerebellar artery supplies the superior surface of the cerebel- lum and the cerebellar nuclei.

Answer 118

A

D. at the vestibular nuclei

In the comatose patient, a lesion at the level of the vestibular nuclei results in extensor movements of the arms and weak flexor movements of the legs. Flaccidity of the lower and upper extremities occurs with lesions below the vestibular nuclei. Lesions above the red nucleus (decorticate) result in flexion of the upper and extension of the lower extremities. Lesions below the red nucleus (and above the vestibular nuclei) result in extensor posturing of all extremities (decerebrate).

Answer 119

A

E. cranial nerve VII reaching the sphenopalatine ganglion

Fibers of the chorda tympani reach the sphenopalatine ganglion to produce
“crocodile tears,” also known as Bogorad’s syndrome

Fibers of the chorda tympani reach the sphenopalatine ganglion to produce “crocodile tears,” also known as Bogorad’s syndrome.

Answer 120

A

A. N13

With a cervical syrinx, one would expect attenuation or abolition of the
cervical N13 evoked potential. N13 attenuation may be due to involvement
of those laminae of the dorsal horn that receive input from large-diameter
mechano-receptor fi bers

With a cervical syrinx, one would expect attenuation or abolition of the cervical N13 evoked potential. N13 attenuation may be due to involvement of those laminae of the dorsal horn that receive input from large-diameter mechano-receptor fibers.

Answer 121

A

C. Wolff ’s law

Wolff ’s law states that a bone develops the structure most suited to resist the
forces acting upon it. Sherrington’s law: every posterior spinal nerve supplies a special region of skin. Jackson’s law: the nerve functions that are latest
developed are the fi rst to be lost. Delpech’s principle: in spondylolisthesis,
when slippage reaches around 30% the anterior inferior part grows at a faster
rate than the overloaded posterior part of the vertebral body. Flourens’ law
deals with nystagmus, not spine biomechanics

Wolff’s law states that a bone develops the structure most suited to resist the forces acting upon it. Sherrington’s law: every posterior spinal nerve sup- plies a special region of skin. Jackson’s law: the nerve functions that are latest developed are the first to be lost. Delpech’s principle: in spondylolisthesis, when slippage reaches around 30% the anterior inferior part grows at a faster rate than the overloaded posterior part of the vertebral body. Flourens’ law deals with nystagmus, not spine biomechanics.

Answer 122

A

D. display all of the above
features

Chordomas tend to be in the midline, whereas chondrosarcomas are more frequently found off the midline (at the petrosphenoid synchondrosis). Chordomas express S-100 only variably. Normal neurological examinations are more
common in patients with chordoma, whereas visual loss, facial numbness, and
multiple cranial neuropathies are more common in patients with chondrosarcoma. These differences probably reflect the tendency of chordomas to originate from the clivus and chondrosarcomas from the temporal bone.

Chordomas tend to be in the midline, whereas chondrosarcomas are more fre- quently found off the midline (at the petrosphenoid synchondrosis). Chordo- mas express S-100 only variably. Normal neurological examinations are more common in patients with chordoma, whereas visual loss, facial numbness, and multiple cranial neuropathies are more common in patients with chondrosar- coma. These differences probably reflect the tendency of chordomas to origi- nate from the clivus and chondrosarcomas from the temporal bone.

Answer 123

A

A. Medically refractory essential tremor

Thalamotomy is quite eff ective for medically refractory essential tremor. The Parkinson’s patients who benefi t most from thalamotomy are usually young,
with tremor-predominant Parkinson’s disease.

Thalamotomy is quite effective for medically refractory essential tremor. The Parkinson’s patients who benefit most from thalamotomy are usually young, with tremor-predominant Parkinson’s disease.

Answer 124

A

D. The midway point between the exit of the dorsal and ventral rootlets

Due to considerable variation in the attachment of the dentate ligament, the best estimate of the equator is the midway point of the dorsal and ventral ootlets. The equator is a useful landmark for the posterior extent of a cordotomy incision and marks the point of the sacralmost fi bers of the spinothalamic tract. The exiting ventral root is about 5 mm from the anterior spinal artery.

Due to considerable variation in the attachment of the dentate ligament, the best estimate of the equator is the midway point of the dorsal and ventral rootlets. The equator is a useful landmark for the posterior extent of a cor- dotomy incision and marks the point of the sacralmost fibers of the spinotha- lamic tract. The exiting ventral root is about 5 mm from the anterior spinal artery.

Answer 125

A

C. 14 months

It usually takes 12 to 18 months for radiation changes to appear on MRI scans.

Answer 126

A

C. the activity of aromatic amino acid decarboxylase is high

L-dopa is converted very quickly to dopamine by aromatic L-amino acid decarboxylase (AADC). Dopamine is converted to norepinephrine (NE) by dopamine beta hydroxylase, which is found in vesicles within the catecholaminergic neuron.

Answer 127

A

A. The length constant is directly proportional to the membrane resistance

The length constant is the distance along a fi ber where a change in the membrane potential produced by a given current decays to a value of approximately one-third of its original value. It is directly proportional to membrane
resistance and inversely related to axial resistance (the resistance of the cytoplasm within the fi ber).

The length constant is the distance along a fiber where a change in the mem- brane potential produced by a given current decays to a value of approxi- mately one-third of its original value. It is directly proportional to membrane resistance and inversely related to axial resistance (the resistance of the cy- toplasm within the fiber).

Answer 128

A

D. Mast cell

Raynaud’s phenomenon is caused by mast cell dysfunction; sympathectomy has not proven helpful. Half of these patients have collagen vascular disease.

Answer 129

A

D. All of the above

Epidural hematomas are the most common intracranial hematoma in children. Although an arterial component is of major concern, diff use oozing from the bone or from the highly vascularized periosteal surface of the dura
is now considered to be a more common source of epidural hematomas in children.

Epidural hematomas are the most common intracranial hematoma in chil- dren. Although an arterial component is of major concern, diffuse oozing from the bone or from the highly vascularized periosteal surface of the dura is now considered to be a more common source of epidural hematomas in children.

Answer 130

A

E. L5

Spondylolysis is a bone defect in the posterior vertebral arch between the upper and lower articular processes, that is, the isthmus or pars interarticularis.

Answer 131

A

B. a nerve arising from the roots of the brachial plexus.

Winged scapula is caused by paralysis of the serratus anterior muscle as a result of damage to the long thoracic nerve that arises from the roots of the
brachial plexus (C5–C7)

Winged scapula is caused by paralysis of the serratus anterior muscle as a result of damage to the long thoracic nerve that arises from the roots of the brachial plexus (C5–C7).

Answer 132

A

A. Vim

The typical thalamotomy target is the Vim (ventralis intermedius) nucleus. Often just inserting the electrode into Vim reduces the tremor (microthalamotomy eff ect), and indicates that the electrode is in a good position

The typical thalamotomy target is the Vim (ventralis intermedius) nucleus. Often just inserting the electrode into Vim reduces the tremor (microth- alamotomy effect), and indicates that the electrode is in a good position.

Answer 133

A

D. All of the above

All are derived from the telencephalon.

Answer 134

A

D. on the medial surface of the parietal lobe

Answer 135

A

E. Sensory defi cit along the rib cage

The MRI represents thoracic diskitis at a midthoracic level. Oftentimes this
can be treated medically. Indications for surgery, however, do include failure
of medical treatments, requirement for identifi cation of off ending agent via biopsy, mass eff ect caused by ompression of the cord, or instability that is caused by an abscess or signifi cant bony estruction. Sensory defi cit alone is not a clear indication for surgical intervention.

The MRI represents thoracic diskitis at a midthoracic level. Oftentimes this can be treated medically. Indications for surgery, however, do include failure of medical treatments, requirement for identification of offending agent via biopsy, mass effect caused by compression of the cord, or instability that is caused by an abscess or significant bony destruction. Sensory deficit alone is not a clear indication for surgical intervention.

Answer 136

A

B. Bipolar cells

Answer 137

A

D. Spiral ganglion

The spiral ganglion consists of bipolar neurons of the cochlear division of the vestibulocochlear nerve.

Answer 138

A

E. Supplementary motor area

The supplementary motor area (area 6) is unique because a lesion in that location is associated with no language output, usually with complete recovery in weeks to months. This is in contrast with the perisylvian language sites.

The supplementary motor area (area 6) is unique because a lesion in that lo- cation is associated with no language output, usually with complete recovery in weeks to months. This is in contrast with the perisylvian language sites.

Answer 139

A

A. the sphenoid bone anterior to the greater and lesser superfi cial petrosal nerves.

During middle fossa approaches, this anatomy can be appreciated. As the dura
is elevated, branches of the middle meningeal artery are encountered, and
the greater and lesser superfi cial petrosal nerves are identifi ed immediately posterior to the foramen spinosum. With careful bone removal, the greater
superfi cial petrosal nerve can be traced back to the geniculate ganglion.

During middle fossa approaches, this anatomy can be appreciated. As the dura is elevated, branches of the middle meningeal artery are encountered, and the greater and lesser superficial petrosal nerves are identified immediately posterior to the foramen spinosum. With careful bone removal, the greater superficial petrosal nerve can be traced back to the geniculate ganglion.

Answer 140

A

E. V

The position of the posterior inferior tip of L5 above one of the quarters characterizes grade I, II, III, or IV spondylolisthesis, respectively (III–V being higher grades).

The position of the posterior inferior tip of L5 above one of the quarters char- acterizes grade I, II, III, or IV spondylolisthesis, respectively (III–V being high- er grades).

Answer 141

A

D. All of the above

Golgi tendon organs detect tension in the muscle fi ber. Aff erent signals are carried by Ib fi bers to interneurons that decrease the alpha motor neuron output.

Golgi tendon organs detect tension in the muscle fiber. Afferent signals are carried by Ib fibers to interneurons that decrease the alpha motor neuron output.

Answer 142

A

D. All of the above

The ventralis intermedius (Vim) is thought to be a relay nucleus for kinesthetic sensation. All observations indicate placement in the Vim. Contralateral paresthesias from stimulation of the Vim occur at higher thresholds than those obtained from the ventralis caudalis (VC) nucleus (posterior to the Vim).

The ventralis intermedius (Vim) is thought to be a relay nucleus for kines- thetic sensation. All observations indicate placement in the Vim. Contralat- eral paresthesias from stimulation of the Vim occur at higher thresholds than those obtained from the ventralis caudalis (VC) nucleus (posterior to the Vim).

Answer 143

A

C. tufted and mitral cells

Glomeruli of the olfactory nerve are composed of mitral and tufted cells. Axons of mitral and tufted cells go on to form the lateral olfactory tract.

Glomeruli of the olfactory nerve are composed of mitral and tufted cells. Ax- ons of mitral and tufted cells go on to form the lateral olfactory tract.

Answer 144

A

A. MCA only

The sylvian triangle is defi ned angiographically by (1) the most posterior branch of the middle cerebral artery as it exits the sylvian fi ssure, (2) branches of superior ramifi cations of the MCA, and (3) inferior loops of the MCA.

The sylvian triangle is defined angiographically by (1) the most posterior branch of the middle cerebral artery as it exits the sylvian fissure, (2) branch- es of superior ramifications of the MCA, and (3) inferior loops of the MCA.

Answer 145

A

D. MAOA and MAOB are associated with the inner mitochondrial membrane.

MAOA and MAOB are associated with the outer mitochondrial membrane.

Answer 146

A

A. Metencephalon

The metencephalon is a secondary vesicle that becomes the pons, cerebellum, and upper part of the fourth ventricle. The myelencephalon becomes the medulla and the lower part of the fourth ventricle

The metencephalon is a secondary vesicle that becomes the pons, cerebel- lum, and upper part of the fourth ventricle. The myelencephalon becomes the medulla and the lower part of the fourth ventricle.

Answer 147

A

A. Tectorial membrane

The tectorial membrane is a projection of the spiral limbus that overlies hair
cells of the organ of Corti. The basilar membrane supports the organ of Corti
and separates the cochlear duct from the scala tympani. The vestibular (Reissner’s membrane) separates the scala vestibuli from the cochlear duct

The tectorial membrane is a projection of the spiral limbus that overlies hair cells of the organ of Corti. The basilar membrane supports the organ of Corti and separates the cochlear duct from the scala tympani. The vestibular (Re- issner’s membrane) separates the scala vestibuli from the cochlear duct.

Answer 148

A

B. Solitary projections to the nucleus ambiguus

Solitary projections to the nucleus ambiguus are largely bilateral and are the
intermediate neurons in the pathway for the gag refl ex.

Solitary projections to the nucleus ambiguus are largely bilateral and are the intermediate neurons in the pathway for the gag reflex.

Answer 149

A

C. Pedicle screw fusion of L4–L5

The film shows a grade I spondylolisthesis at L4–L5. Although management of this problem is wide ranging, from the choices given the best management is a pedicle screw fusion at the concerning levels (L4–L5)

The film shows a grade I spondylolisthesis at L4–L5. Although management of this problem is wide ranging, from the choices given the best management is a pedicle screw fusion at the concerning levels (L4–L5).

Answer 150

A

B. GABA-B

The GABA-B receptor is activated by the GABA analogue baclofen, is not chloride dependent, and is bicuculline insensitive. GABA-C is found in the retina, hippocampus, and cerebellum, and is insensitive to baclofen and bicuculline

The GABA-B receptor is activated by the GABA analogue baclofen, is not chlo- ride dependent, and is bicuculline insensitive. GABA-C is found in the retina, hippocampus, and cerebellum, and is insensitive to baclofen and bicuculline.

Answer 151

A

C. Cranial nerve IV

Structures that pass above the tendinous ring are the lacrimal nerve, frontal nerve, and CN IV (trochlear)

Structures that pass above the tendinous ring are the lacrimal nerve, frontal nerve, and CN IV (trochlear).

Answer 152

A

C. Staphylococcus

The most common causative organism of brain abscesses in trauma is Staphylococcus.

Answer 153

A

B. Streptococcus

The most common causative organism of brain abscesses in adults due to chronic otitis is Streptococcus

The most common causative organism of brain abscesses in adults due to chronic otitis is Streptococcus.

Answer 154

A

A. Proteus

The most common causative organisms of brain abscesses in neonates are Citrobacter, Bacteroides, Proteus and gram-negative bacilli

The most common causative organisms of brain abscesses in neonates are Citrobacter, Bacteroides, Proteus and gram-negative bacilli.

Answer 155

A

A. an inhibitor of MAOA.

Tranylcypromine is an inhibitor of MAOA. Deprenyl is a specifi c inhibitor of MAO

Tranylcypromine is an inhibitor of MAOA. Deprenyl is a specific inhibitor of MAOB.

Answer 156

A

B. Floor plate
The floor plate contains the ventral white commissure

The floor plate contains the ventral white commissure.

Answer 157

A

E. Abnormalities of chromosome 9 are seen

Sturge–Weber syndrome occurs sporadically without Mendelian inheritance and is of unknown etiology.

Answer 158

A

E. All of the above

There are nonchoroid plexus sites of cerebrospinal fluid (CSF) production. Likewise there are sites of absorption other than the arachnoid granulations
(paranasal sinuses, cervical lymphatics, exiting nerve roots, and transependymal flow)

There are nonchoroid plexus sites of cerebrospinal fluid (CSF) production. Likewise there are sites of absorption other than the arachnoid granulations (paranasal sinuses, cervical lymphatics, exiting nerve roots, and transepend- ymal flow).

Answer 159

A

C. 15%

In patients with known systemic cancer, 10–15% of single brain lesions are cerebral abscesses or primary brain tumors.

Answer 160

A

A. GABA breakdown.

Vigabatrin interferes with GABA breakdown, whereas tiagabine interferes with GABA reuptake

Vigabatrin interferes with GABA breakdown, whereas tiagabine interferes with GABA reuptake.

Answer 161

A

B. the hippocampus.

Answer 162

A

B. lateral.

Lesions placed too laterally during thalamotomy risk injury to the internal capsule (posterior limb). Lesions placed too posterior may cause contralateral hemisensory defi cits owing to injury of the ventralis caudalis (VC) nucleus.

Lesions placed too laterally during thalamotomy risk injury to the internal capsule (posterior limb). Lesions placed too posterior may cause contralater- al hemisensory deficits owing to injury of the ventralis caudalis (VC) nucleus.

Answer 163

A

B. Cyclosporine
Cyclosporine along with some of the newer immunosuppressive agents (FK-506 or tacrolimus) work at the level of the T cells by inhibiting expression of IL-2.

Cyclosporine along with some of the newer immunosuppressive agents (FK-506 or tacrolimus) work at the level of the T cells by inhibiting expression of IL-2.

Answer 164

A

E. P1

The perforating arteries from the Pcom are termed the anterior thalamo-perforating arteries. Those from the P1 are called the posterior thalamo-perforating arteries. Those from P2 are termed the thalamo-geniculate arteries.

The perforating arteries from the Pcom are termed the anterior thalamo-perforating arteries. Those from the P1 are called the posterior thalamo-perforating arteries. Those from P2 are termed the thalamo-genicu- late arteries.

Answer 165

A

D. Arcuate

Answer 166

A

E. Nucleus ambiguus
The basal plate gives rise to the hypoglossal nucleus, nucleus ambiguus, dorsal motor nucleus of the vagal nerve, and inferior salivatory nucleus

The basal plate gives rise to the hypoglossal nucleus, nucleus ambiguus, dor-
sal motor nucleus of the vagal nerve, and inferior salivatory nucleus.

Answer 167

A

B. 20–45°

Answer 168

A

B. Kocher’s point.
Kocher’s point places the atheter in the frontal horn of the lateral ventricle. One can measure 1 cm anteriorly to the coronal suture or 3.5 cm in front of the bregma. This precaution is to avoid the motor strip. Keen’s point would be used for placement of the catheter in the trigone and would require entrance through the posterior parietal region

Kocher’s point places the catheter in the frontal horn of the lateral ventricle. One can measure 1 cm anteriorly to the coronal suture or 3.5 cm in front of the bregma. This precaution is to avoid the motor strip. Keen’s point would be used for placement of the catheter in the trigone and would require en- trance through the posterior parietal region.

Answer 169

A

B. Ipsilateral Horner’s syndrome

The MRI demonstrates absent flow voids in the left vertebral artery, a finding seen in Wallenberg syndrome.

Answer 170

A

C. Clonazepam

Clonazepam acts by increasing GABA-A opening frequency and does not have any hepatic enzyme–inducing properties.

Answer 171

A

A. the contralateral red nucleus

Answer 172

A

E. Postural instability
Freezing episodes and postural instability do not appear to be improved with
pallidotomy

Freezing episodes and postural instability do not appear to be improved with
pallidotomy.

Answer 173

A

C. Neurological complications are the presenting feature of AIDS in 20% of cases

Neurological involvement in HIV infection is more common in children than in adults. Neurological complications occur in > 40% of patients with HIV
infection. They are the presenting feature of AIDS in 10–20% of patients. The prevalence of neuropathological abnormalities upon autopsy is 80%. Although an ongoing decline in HIV-associated CNS disease has been seen in
very recent years, the mortality from these diseases remains elevated

Neurological involvement in HIV infection is more common in children than in adults. Neurological complications occur in > 40% of patients with HIV infection. They are the presenting feature of AIDS in 10–20% of patients. The prevalence of neuropathological abnormalities upon autopsy is 80%. Al- though an ongoing decline in HIV-associated CNS disease has been seen in very recent years, the mortality from these diseases remains elevated.

Answer 174

A

C. proximal two-thirds of the basilar artery.

Answer 175

A

B. The majority of body stores of serotonin are found in the central nervous system.

Serotonin is found in many cells that are not neurons, such as platelets, mast cells, and enterochromaffi n cells. In fact, the brain accounts for only about 1%
of body stores of serotonin.

Serotonin is found in many cells that are not neurons, such as platelets, mast cells, and enterochromaffin cells. In fact, the brain accounts for only about 1% of body stores of serotonin.

Answer 176

A

E. Superior colliculus

The alar plate gives rise to the layers of the superior colliculus and to the nuclei of the inferior colliculus.

Answer 177

A

A. Tumor necrosis factor-alpha and interleukin (IL)-8

Studies comparing nucleus pulposus material from disk herniation versus
painful degenerative disk disease have shown that protein expression of
tumor necrosis factor-α (TNF-α) and interleukin (IL)-8 is increased in the degenerative disk disease group, and both groups had similar levels of IL-1β, IL-6, and IL-12. Therefore, TNF-α and IL-8 may be promising candidates to
treat patients with diskogenic back pain on a molecular level.

Studies comparing nucleus pulposus material from disk herniation versus painful degenerative disk disease have shown that protein expression of tumor necrosis factor-α (TNF-α) and interleukin (IL)-8 is increased in the degenerative disk disease group, and both groups had similar levels of IL-1β, IL-6, and IL-12. Therefore, TNF-α and IL-8 may be promising candidates to treat patients with diskogenic back pain on a molecular level.

Answer 178

A

D. Transversalis fascia

When dissecting below the arcuate line, the transversalis fascia is the only fascial layer between the rectus abdominis and the peritoneum

When dissecting below the arcuate line, the transversalis fascia is the only fascial layer between the rectus abdominis and the peritoneum.

Answer 179

A

B. Ependymoma

Cranial neuropathies are a more common presenting sign of ependymomas than other tumors due to their tendency to arise from the fl oor of the fourth ventricle. Medulloblastomas typically arise from the inferior medullary velum.

Cranial neuropathies are a more common presenting sign of ependymo- mas than other tumors due to their tendency to arise from the floor of the fourth ventricle. Medulloblastomas typically arise from the inferior medul- lary velum.

Answer 180

A

D. All of the above

Lissauer’s tract caps the dorsal horns, and these fi bers terminate in the substantia gelatinosa (lamina II

Lissauer’s tract caps the dorsal horns, and these fibers terminate in the sub- stantia gelatinosa (lamina II).

Answer 181

A

B. at the junction of the insula and the frontal lobe.

The limen insula is part of the primary olfactory cortex and is found at the junction of the insular and frontal lobe cortex.

Answer 182

A

C. optic tract.

If the electrode is correctly placed, visual thresholds are usually between 2 and 3 V. Higher values indicate that the electrode is too far superior. Lower values indicate that the electrode is too far inferior.

Answer 183

A

B. lateral mesencephalic vein.

Answer 184

A

B. Glutamate

Answer 185

A

A. It is transmitted in an autosomal recessive pattern.

In stiff person syndrome, the stiff ness primarily aff ects the truncal muscles and is superimposed by spasms, resulting in postural deformities. Chronic pain, impaired mobility, and lumbar hyperlordosis are common symptoms. The pattern of inheritance is unknown. Patients generally have high amounts
of glutamic acid decarboxylase antibody titers.

In stiff person syndrome, the stiffness primarily affects the truncal muscles and is superimposed by spasms, resulting in postural deformities. Chronic pain, impaired mobility, and lumbar hyperlordosis are common symptoms. The pattern of inheritance is unknown. Patients generally have high amounts of glutamic acid decarboxylase antibody titers.

Answer 186

A

B. IL-3

Inflammatory mediators including interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor-α are expressed at higher levels in “diseased” intervertebral dis

Inflammatory mediators including interleukin (IL)-1β, IL-6, IL-8, and tumor ne- crosis factor-α are expressed at higher levels in “diseased” intervertebral disks.

Answer 187

A

E. All of the above

Answer 188

A

A. Low levels of prolactin

Answer 189

A

D. Elevated adrenocorticotrophic hormone

Enlarged pituitary stalk may be due to sarcoidosis, which can present with elevated angiotensin-converting enzyme levels. It may also be due to Langerhans cell histiocytosis, which may present with eosinophilic granuloma. It
can occur in cases of meningitis in children. It is very rarely associated with primary pituitary tumors.

Enlarged pituitary stalk may be due to sarcoidosis, which can present with elevated angiotensin-converting enzyme levels. It may also be due to Langer- hans cell histiocytosis, which may present with eosinophilic granuloma. It can occur in cases of meningitis in children. It is very rarely associated with primary pituitary tumors.

Answer 190

A

D. only the contralateral lower face

Central facial palsy is usually characterized by either hemiparalysis or hemi- paresis of the contra-lateral muscles in facial expression. Muscles on the forehead are typically intact. Patients have lost voluntary control of muscle movement in the face; however, muscles in the face involved in spontaneous emotional expression usually remain intact.

Answer 191

A

C. the middle cerebellar peduncle.

Answer 192

A

A. completeness of primary tumor excision and extent of involvement at presentation.
B. TP53 overexpression.
C. the presence of Homer–Wright rosettes on pathology.
D. neuron-specifi c enolase expression.
E. destruction of the cribriform plate.

Esthesioneuroblastoma has a variable outcome that is primarily prognosti- cated by the extent of involvement at presentation (Kadish stage and lymph nodes metastasis) and completeness of resection.

Answer 193

A

A. increased latency in wave 3.
B. decreased latency in wave 4.
C. decreased latency in wave 5.
D. increased latency in wave 4.
E. increased latency in wave 5.

Brainstem auditory evoked potentials (BSAEP) measure the timing of electrical waves from the brainstem in response to clicks or tone bursts in the ear. Com- puter averaging over time filters background noise to generate an averaged re- sponse of the auditory pathway to an auditory stimulus. Three waves (I, III and V) are plotted for each ear. The waveform represents specific anatomical points along the auditory neural pathway: the cochlear nerve and nuclei (waves I and II), superior olivary nucleus (wave III), lateral lemniscus (wave IV), and inferior colliculi (wave V). The most reliable indicator of retraction during vestibular schwannoma surgery from the BSAEP is the interaural latency differences in wave V; the latency in the abnormal ear is prolonged.

Answer 194

A

B. pyramidal cells of the cerebral cortex
C. pyramidal cells of the hippocampus.
D. septal region.
E. lateral entorhinal cortex

Answer 195

A

A. They receive group Ia primary aff erent fibers.
B. They receive group II secondary aff erent fibers.
C. They are associated with fl ower spray endings.
D. They are associated with static gamma efferent fibers.
E. They respond to muscle tension

Golgi tendon organs are sensitive to muscle tension.

Answer 196

A

A. cysticercosis.
B. histoplasmosis.
C. Lyme disease.
D. mucormycosis
E. hydatid disease.

Lyme disease is an inflammatory disease caused by the spirochetes Borrelia burgdorferi, which are transmitted by the bite of infected Ixodes ticks. Lyme disease is endemic in Massachusetts, Connecticut, Maine, New Hampshire, Rho- de Island, New York, New Jersey, Pennsylvania, Delaware, Maryland, Michigan, and Wisconsin. It is categorized into early localized, early disseminated, and late. There may be an erythema migrans or systemic complaints in the early localized phase. Early disseminated Lyme disease can present with many central nervous system manifestations, including meningitis, altered mental status, radiculop- athy and cranial neuropathy. If left untreated, sequelae include rheumatologic symptoms (monoarticular or oligoarticular arthritis) in 60%, neurologic signs and symptoms in 10%, and cardiac complications in 5% of cases.

Answer 197

A

A. It is a well-described complication of VP shunts.
B. It is due to deposition of immune complexes in the glomeruli of kidneys.
C. The diagnosis is suspected with hematuria, elevated erythrocyte sedimentation rate (ESR), and decreased complement levels.
D. Proper treatment entails removing the entire shunt.
E. There is an elevated peripheral WBC count

Shunt nephritis is a well-described complication of ventriculoatrial (VA) shunts. VA shunt complications are much more severe and potentially life-threatening than ventriculoperitoneal (VP) shunt complications.

Answer 198

A

A. Male predominance has been noted.
B. It is a surgically curable cause of partial seizures.
C. There is an abundance of mitoses with no necrosis.
D. It is a mixed glial and neuronal neoplasm.
E. It shows on CT scans as a hypodense pseudocystic lesion

There is a paucity of mitoses and no necrosis in dysembryoplastic neuroepi- thelial tumors (DNET).

Answer 199

A

A. Transsphenoidal resection
B. Bromocriptine
C. Angiography
D. Ophthalmologic evaluation
E. Transcranial resection

The patient likely presents with an adrenocorticotropic hormone (ACTH)-secreting macroadenoma. Proper evaluation prior to surgery includes ophthalmologic and endocrine consultations and an endocrine panel of laboratory tests.

Answer 200

A

D. Inferior, inferior

Answer 201

A

A. Olivocerebellar
B. Reticulocerebellar
C. Dorsal spinocerebellar
D. All of the above
E. None of the above

All of the information that is passed between the brainstem and the cerebel- lum enters and exits through one of three cerebellar peduncles: (1) inferior cerebellar peduncle or restiform body at the level of the medulla, (2) middle cerebellar peduncle or brachium pontis at the level of the pons, (3) superior cerebellar peduncle or brachium conjunctivum at the level of the midbrain. The vestibulocerebellar tract traverses the juxtarestiform body.

Answer 202

A

A. n-Myc amplifi cation.
B. 1p deletion.
C. TrkA expression.
D. older age.
E. None of the abo

Higher levels of TrkA are seen in neuroblastomas with favorable histology. The other factors listed are associated with a worse prognosis in neuroblastomas.

Answer 203

A

A. mastoid tip.
B. key hole.
C. asterion
D. bregma.
E. lambda

Answer 204

A

A. acetyl CoA.
B. acetylcholinesterase.
C. choline acetyltransferase.
D. choline.
E. sensitivity to hemicholinium-3.

Choline acetyltransferase is the definitive marker for cholinergic neurons.
Hemicholimium-3 blocks the high-affinity cholinergic reuptake process.

Answer 205

A

Tanycytes are most likely to be found in

Tanycytes are a variety of ependymal cells found in the wall of the third ven- tricle. The tanycyte is a cell with intermediate features between astrocytes and ependymal cells.

Answer 206

A

C.C

The diagram shown represents the lumbar plexus, structure A is the ilioin- guinal nerve, B is the genitofemoral nerve, C is the lateral femoral cutaneous nerve, D is the femoral nerve, and E is the obturator nerve.

Answer 207

A

A. between the pyramid and the olive.
B. between the olive and the inferior cerebellar peduncle.
C. from the same sulcus as CN XII.
D. from the dorsomedial sulcus.
E. from none of the above.

Answer 208

A

B. prosoprognosia

Facial agnosia (prosoprognosia) results from bilateral damage to the medial basal occipitotemporal cortex

Facial agnosia (prosoprognosia) results from bilateral damage to the medial
basal occipitotemporal cortex.

Answer 209

A

A. spinal cord compression.
B. Ondine’s curse.
C. opsoclonus syndrome.
D. diarrhea.
E. All of the above

All of the above may be the presentation in children with neuroblastomas. Diarrhea is from vasoactive intestinal polypeptide (VIP) secretion by the tu- mor. Ondine’s curse results from impaired autonomic control of respiration.

Answer 210

A

A. the results of the Goldman perimetry fi eld.
B. being male.
C. the preoperative prolactin level.
D. the age of the patient.
E. being female.

Answer 211

A

A. conversion of R-arginine into nitrous oxide (NO).
B. conversion of citrulline into NO.
C. production of NO and L-arginine.
D. production of NO and citrulline.
E. None of the above

The synthesis of NO (nitrous oxide) involves the conversion of L-arginine into NO and citrulline. All three isoforms of nitric oxide synthase (NOS) require tetrahydrobiopterin as a cofactor and NADPH as a coenzyme.

Answer 212

A

A. I
B. II
C. III and IV
D. VII
E. IX

The substantia gelatinosa (Rexed lamina II) is found at all cord levels and is homologous to the spinal trigeminal tract. It is associated with light touch, pain, and temperature sensation, and it integrates input for the ventral and lateral spinothalamic tracts.

Answer 213

A

A. an intracranial bruit with heart failure.
B. subarachnoid hemorrhage.
C. hydrocephalus.
D. developmental delay.
E. ocular symptoms.

Vein of Galen malformation may be defined as a direct arteriovenous (AV) fistula between choroidal and/or quadrigeminal arteries and an overlying single median venous sac; it is rare, representing only < 1% of all intracrani- al arteriovenous malformations (AVMs). Neonatal patients present with an abrupt onset of high-output cardiac failure; as much as 80% of the cardiac output may pass through the fistula. An audible bruit may be present. An- other type of vein of Galen malformation (VOGM) (presenting with ocular symptoms and developmental delay) is typically thalamic or midbrain with deep drainage to the vein of Galen (VOG).

Answer 214

A

A. Subarachnoid hemorrhage
B. Progressive ascending paraplegic syndrome
C. The defi nitive therapy is microsurgical elimination.
D. Tendency to bleed in elderly patients
E. It may represent a vascular anomaly

The scan demonstrates an intramedullary cavernoma. These lesions tend to bleed in patients of young age, show a clear sensory level, present with suba- rachnoid hemorrhage or by progressive ascending paraplegic syndrome. The definitive therapy is microsurgical elimination.

Answer 215

A

B. The arcuate eminence is a prominence on the anterior surface of the petrous
portion of the temporal bone corresponding to the position of the superior semicircular canal.

The arcuate eminence is a prominence on the anterior surface of the petrous portion of the temporal bone corresponding to the position of the superior semicircular canal.

Answer 216

A

A. It is a branch of the posterior cerebral artery.
B. It supplies the choroid plexus of the third ventricle.
C. It supplies the choroid plexus of the lateral ventricles.
D. All of the above
E. None of the above

Answer 217

A

A. in the third ventricle.
B. in the fourth ventricle.
C. in the lateral ventricle.
D. at the cauda equina.
E. in none of the above.

The calamus scriptorius is an anatomic structure along the inferior part of
the rhomboid fossa; the narrow lower end of the fourth ventricle between the two clavae

The calamus scriptorius is an anatomic structure along the inferior part of the rhomboid fossa; the narrow lower end of the fourth ventricle between the two clavae.

Answer 218

A

A. alpha waves.
B. beta waves.
C. theta waves.
D. delta waves.
E. None of the above

Delta waves occur with deep sleep, infancy, and brain disease

Delta waves occur with deep sleep, infancy, and brain disease.

Answer 219

A

A. VII, IX, X
B. IX, X
C. IX, X, XII
D. VII, X
E. VII, IX, XII

The stylohyoid is innervated by VII. The styloglossus is innervated by XII. The stylopharyngeus is innervated by IX.

The stylohyoid is innervated by VII. The styloglossus is innervated by XII. The
stylopharyngeus is innervated by IX.

Answer 220

A

A. C7 plumb line
B. Cobb angle
C. Pelvic tilt
D. Sacral slope
E. None of the above

A. The sagittal vertical axis is the distance between the C7 plumb line and the
posterosuperior corner of S1 in the sagittal plane

The sagittal vertical axis is the distance between the C7 plumb line and the posterosuperior corner of S1 in the sagittal plane.

Answer 221

A

A. a painful response is produced by an innocuous mechanical stimulus.
B. a painful response is felt in an amputated limb.
C. a painful response is felt on the opposite side of the body.
D. there is sensitization of spinocerebellar neurons.
E. all of the above may occur.

Allodynia is a condition in which a painful response is produced by an innocuous mechanical stimulation. It is the result of sensitization of spinothalamic
neurons in the dorsal horn and the failure of descending systems to control
the activity of these neurons. Alloesthesia is characterized by a painful stimulus on one side of the body that is thought to be on the other

Allodynia is a condition in which a painful response is produced by an innoc- uous mechanical stimulation. It is the result of sensitization of spinothalamic neurons in the dorsal horn and the failure of descending systems to control the activity of these neurons. Alloesthesia is characterized by a painful stim- ulus on one side of the body that is thought to be on the other side.

Answer 222

A

A. I
B. II
C. III and IV
D. VII
E. IX

Clarke’s nucleus is found at the base of the dorsal horn and corresponds to Rexed VII lamina. Clarke’s column extends from C8 or T1 to about L3. Clarke’s nucleus is homologous to the accessory cuneate nucleus of the medulla. It subserves unconscious proprioception from the muscle spindles and Golgi tendon organs and is the origin of the dorsal spinocerebellar tract

Clarke’s nucleus is found at the base of the dorsal horn and corresponds to Rexed VII lamina. Clarke’s column extends from C8 or T1 to about L3. Clarke’s nucleus is homologous to the accessory cuneate nucleus of the medulla. It subserves unconscious proprioception from the muscle spindles and Golgi tendon organs and is the origin of the dorsal spinocerebellar tract.

Answer 223

A

A. Occipital encephaloceles are the most common type.
B. Frontoethmoidal (sincipital) are the most common type in southeast Asia
and among Australian aborigines.
C. Parietal encephaloceles are associated with Chiari II malformation in up to
one-third of cases.
D. Basal encephaloceles are associated with defects along the sphenoid bone.
E. Children with basal encephaloceles have a low risk of developing meningitis

Basal encephaloceles should be treated as early as possible. Children with
basal encephaloceles in the nasopharynx are at signifi cant risk of developing
meningitis

Basal encephaloceles should be treated as early as possible. Children with basal encephaloceles in the nasopharynx are at significant risk of developing meningitis

Answer 224

A

A. the thalamus and the globus pallidus.
B. the caudate nucleus and the corpus striatum.
C. the caudate and the thalamus.
D. the thalamus and the putamen
E. None of the above

The anterior limb of the internal capsule (on horizontal section) can be found
between the caudate nucleus and the corpus striatum (globus pallidus and
putamen). Clinically important tracts lie in the genu and posterior limb. The
posterior limb (on horizontal section) can be found between the thalamus
and the corpus striatum (globus pallidus and putamen). The posterior limb
of the internal capsule contains corticospinal fi bers.

The anterior limb of the internal capsule (on horizontal section) can be found between the caudate nucleus and the corpus striatum (globus pallidus and putamen). Clinically important tracts lie in the genu and posterior limb. The posterior limb (on horizontal section) can be found between the thalamus and the corpus striatum (globus pallidus and putamen). The posterior limb of the internal capsule contains corticospinal fibers.

Answer 225

A

A.A
B.B.
C.C
D.D
E.E

Answer 226

A

A.A
B.B.
C.C
D.D
E.E

Answer 227

A

A.A
B.B.
C.C
D.D
E.E

Answer 228

A

A.A
B.B.
C.C
D.D
E.E

Answer 229

A

A. It emerges inferior to the inferior obliquus capitis muscle.
B. It is accompanied by the occipital artery.
C. It is a sensory nerve.
D. All of the above
E. None of the above

The greater occipital nerve is a sensory nerve from the dorsal ramus of C2.

Answer 230

A

A. Aspirin inhibits both cyclooxygenase (COX) isoforms.
B. Arachidonic acid is a substrate for production of ceramide.
C. Thromboxane synthesis inhibitors lead to depletion of arachidonic acid.
D. Arachidonic acid is a substrate for COX I.
E. Prostaglandin H2PGH2 is a product of the COX enzyme.

Thromboxane synthesis inhibitors lead to a buildup of arachidonic acid

Thromboxane synthesis inhibitors lead to a buildup of arachidonic acid.

Answer 231

A

A. subthalamic nucleus.
B. substantia nigra pars compacta.
C. substantia nigra pars reticulata.
D. globus pallidus interna.
E. globus pallidus externa

C. The lateral portion of the substantia nigra pars reticulata (SNpr) is connected with cortical and brainstem areas that control eye movements. SNpr is
GABAergic and inhibitory to the VLm (medial part of the ventrolateral thalamus) and VAmc (magnocellular part of the ventral anterior thalamus)

The lateral portion of the substantia nigra pars reticulata (SNpr) is connect- ed with cortical and brainstem areas that control eye movements. SNpr is GABAergic and inhibitory to the VLm (medial part of the ventrolateral thala- mus) and VAmc (magnocellular part of the ventral anterior thalamus).

Answer 232

A

A. Dorsal lateral sulcus
B. Dorsal intermediate sulcus
C. Ventral lateral sulcus
D. Dorsal median sulcus
E. Ventral intermediate sulcus

A. The dorsal lateral sulcus receives the dorsal roots

The dorsal lateral sulcus receives the dorsal roots.

Answer 233

A

A. Biopsy is usually indicated to confi rm the diagnosis.
B. Hyperfractionated radiation therapy has not been shown to improve
survival.
C. It represents 30% of pediatric CNS tumors.
D. There is no proven chemotherapeutic regimen.
E. Most lesions will regress spontaneously

D. The scan shows a diff usely enhancing brainstem glioma. Biopsy is usually not recommended in this case. Hyperfractionated radiation therapy has been shown to improve survival. Brainstem gliomas represent 10–20% of
childhood CNS tumors. There are currently no proven chemotherapeutic regimens.

The scan shows a diffusely enhancing brainstem glioma. Biopsy is usual- ly not recommended in this case. Hyperfractionated radiation therapy has been shown to improve survival. Brainstem gliomas represent 10–20% of childhood CNS tumors. There are currently no proven chemotherapeutic regimens.

Answer 234

A

A. PT = PI + SS
B. PI = PT + SS
C. SS = PI + PT
D. PT = PI − SS
E. SS = PI ÷ PT

Pelvic incidence: the angle between the perpendicular to the sacral plate at its midpoint and the line connecting this point to the middle axis of the femoral heads. It is an anatomical parameter, unique to each individual,
independent of the spatial orientation of the pelvis. Sacral slope: the angle between the superior plate of S1 and a horizontal line. Pelvic tilt: the angle between the line connecting the midpoint of the sacral plate to the axis of the femoral heads, and the vertical.

Pelvic incidence: the angle between the perpendicular to the sacral plate at its midpoint and the line connecting this point to the middle axis of the femoral heads. It is an anatomical parameter, unique to each individual, independent of the spatial orientation of the pelvis. Sacral slope: the angle between the superior plate of S1 and a horizontal line. Pelvic tilt: the angle between the line connecting the midpoint of the sacral plate to the axis of the femoral heads, and the vertical.

Answer 235

A

A. Men may not seek early attention despite loss of libido and potency,
headache, or fatigue.
B. When visual loss or disturbing endocrine symptoms are present most seek
medical attention.
C. A useful endocrine test is determination of the basal serum prolactin level.
D. The normal level ranges from 5 to 20 ng/mL.
E. When the level of prolactin is normal post-treatment, ovulation and menstruation return in < 50% of women in galactorrhea cases

E. The MRI represents a midsagittal section demonstrating a large sellar and suprasellar mass that is compressing the optic chiasm. Slightly elevated prolactin level may be secondary to the stalk eff ec

The MRI represents a midsagittal section demonstrating a large sellar and suprasellar mass that is compressing the optic chiasm. Slightly elevated pro- lactin level may be secondary to the stalk effect.

Answer 236

A

A. Exercise
B. Stress
C. Sleep
D. Pregnancy
E. Delivery

Answer 237

A

A. 10%
B. 20%
C. 40%
D. 70%
E. 90%

Answer 238

A

A. It is also called dysplastic gangliocytoma of the cerebellum.
B. There is demyelination of granular cell layer of the cerebellum.
C. There is thickening of one or more cerebellar folia.
D. Calcifi cation and hydrocephalus may occur in this disorder.
E. A laminated pattern of folia on T2-MRI scans is suggestive of the disease

B. Lhermitte–Duclos disease is an uncommon cerebellar dysplasia that is characterized by hypertrophy of granular-cell neurons, and axonal hypermyelination in the molecular layer. Also known as dysplastic gangliocytoma of the
cerebellum, it may occur in the setting of Cowden disease caused by a PTEN germline mutation

Lhermitte–Duclos disease is an uncommon cerebellar dysplasia that is char- acterized by hypertrophy of granular-cell neurons, and axonal hypermyeli- nation in the molecular layer. Also known as dysplastic gangliocytoma of the cerebellum, it may occur in the setting of Cowden disease caused by a PTEN germline mutation.

Answer 239

A

A. Unilateral symptoms
B. Sensory defi cit
C. Decreased corneal refl ex
D. All of the above
E. None of the above

A. There is no sensory defi cit and no decrease in corneal refl ex. There are no other symptoms in the other cranial nerve

There is no sensory deficit and no decrease in corneal reflex. There are no other symptoms in the other cranial nerves.

Answer 240

A

A. cranioplasty.
B. endovascular procedures.
C. topical wound dressings.
D. vasospasm in the ICU.
E. spinal fusion.

B. The liquid embolic agent n-butyl cyanoacrylate is used in interventional neuroradiology. The embolic agents that are particulate in nature include polyvinyl alcohol, platinum coils, and silk thread.

The liquid embolic agent n-butyl cyanoacrylate is used in interventional neuroradiology. The embolic agents that are particulate in nature include polyvinyl alcohol, platinum coils, and silk thread.

Answer 241

A

A. 15.
B. 14.
C. 13.
D. 12.
E. 11

The Glasgow Coma Scale score (GCS score) in this case would be 13. Eyes open to speech (3), the patient is confused (4), and he obeys motor commands (6)

Answer 242

A

A. Midcervical
B. Upper thoracic
C. Lower thoracic
D. Lumbar
E. Sacra

The ciliospinal center of Budge is found in the lateral horn at T1. This is a sympathetic nucleus that innervates the radial muscle of the iris (dilator pu- pillae) and the nonstriated superior and inferior (Müller) muscles.

Answer 243

A

A. Cimetidine
B. Chloramphenicol
C. Valproic acid
D. Uremia
E. Aspirin

Aspirin decreases all anticonvulsant levels.

Answer 244

A

A. Pain and temperature of the body
B. Pain and temperature of the face
C. Horner’s syndrome
D. Falling
E. None of the above

Posterior inferior cerebellar artery (PICA) syndrome causes decreased contralateral pain and temperature of the body.

Answer 245

A

A. Clay shoveler’s fracture
B. Wedge fracture
C. Teardrop fracture
D. Chance fracture
E. None of the above

Teardrop fractures occur when a fracture occurs on the anteroinferior edge of the vertebral body. The injury is due to hyperflexion and is unstable. Tear- drop fractures are associated with anterior cord syndrome.

Answer 246

A

A. Lacerations in the gland with attendant subcapsular bleeding make it difficult if not impossible to detect the subtle differences between the normal gland and a small tumor.
B. Prolactin microadenomas are usually situated medially in the gland.
C. Larger pituitary tumors usually erode the floor of the sella turcica, and in these cases the tumor may extrude into the operative wound upon removal of the fl oor of the sella and opening of the dura mater.
D. Frequently, the pituitary gland is compressed and flattened against the dorsum sellae or diaphragma sellae by tumor.
E. Reported incidence of postoperative CSF rhinorrhea is ~3%.

Answer 247

A

A. Pia
B. Dura
C. Arachnoid
D. Glia
E. Ependyma

Dura and blood vessels are formed from mesoderm.

Answer 248

A

A. meningioma.
B. oligodendroglioma.
C. astrocytoma.
D. ependymoma.
E. None of the above

The most common primary septal tumor is astrocytoma.

Answer 249

A

A. AICA
B. PICA
C. SCA
D. Satellite veins
E. None of the above

The superior cerebellar artery is the most commonly conflicting artery in trigeminal neuralgia.

Answer 250

A

A. vertebrobasilar ischemia.
B. controlling ICP
C. vasospasm.
D. tumor biology.
E. None of the above

The ELANA technique (excimer laser-assisted nonocclusive anastomosis) may be used to anastomose arteries.

Answer 251

A

A. metastatic disease.
B. jumped facet.
C. burst fracture.
D. teardrop fracture.
E. epidural abscess.

This MRI scan demonstrates a unilateral jumped facet with rotation in the cervical cord, compromising the spinal canal.

Answer 252

A

A. Spetzler–Martin grade 3
B. Spetzler–Martin grade 3A
C. Spetzler–Martin grade 4
D. Spetzler–Martin grade 4A
E. Spetzler–Martin grade 5

This particular AVM is best-graded 4A. Its medium size (2), eloquent location (1), and deep drainage (1) place it as a Spetzler–Martin grade 4. The fact that it has stenotic venous drainage gives it a subclassification of 4A

Answer 253

A

A. Apneustic
B. Biot
C. Central neurogenic hyperventilation
D. Kussmaul
E. Cheyne–Stokes

Biot (irregular breathing) is caused by a lesion in the dorsomedial medulla.

Answer 254

A

A. Globus pallidus externa, posterior limb of the internal capsule
B. Globus pallidus interna, posterior limb of the internal capsule
C. Globus pallidus externa, anterior limb of the internal capsule
D. Globus pallidus interna, anterior limb of the internal capsule
E. None of the above

The anterior choroidal artery supplies the internal globus pallidus, posterior limb of the internal capsule, and temporal horn of the choroid plexus.

Answer 255

A

A. is due to repetitive usage.
B. causes aching and fatiguing of the muscles involved.
C. causes nocturnal exacerbations.
D. exhibits numbness in the palm area.
E. is a better candidate for surgery

Pronator teres syndrome is different from carpal tunnel syndrome in that patients with pronator teres syndrome exhibit numbness in the palm, and nocturnal exacerbations are rare.

Answer 256

A

A. Weakness in the upper extremities
B. Loss of temperature sensation in lower extremities
C. Horner’s sign
D. Gait disturbances
E. Diplopia

The MRI scan represents a brain midsagittal section demonstrating descent of the cerebellar vermis or tonsils consistent with a Chiari malformation, given the age of the patient and the absence of other findings (e.g., hydro- cephalus or medullary kinking), this most likely represents a Chiari type 1 malformation.

Answer 257

A

A. Herniation of cerebellar hemispheres
B. CSF leak
C. Respiratory depression
D. Vascular injury to the posterior inferior cerebellar artery
E. Postoperative wound infection

Answer 258

A

A. Patients presenting with pain generally respond well to surgery.
B. Weakness is most likely to improve with surgery as compared with pain
and sensory defi cits.
C. Sensation may improve when the posterior columns are unaff ected.
D. The most favorable results occurred in patients with cerebellar syndrome.
E. Factors that correlate with a worse outcome include ataxia, scoliosis, and
symptoms lasting longer than 2 years

Answer 259

A

A. V1only
B. V2 only
C. V3 only
D. V2 and V3
E. V1, V2, and V3

Although it is true that the pain starts at V2 (the lower side of the nose) and then involves V3 and V1, it is only necessary to treat the trigger zone.

Answer 260

A

A. Agraphia without alexia
B. Left–right confusion
C. Finger agnosia
D. Acalculia
E. Astereognosis

Gerstmann’s syndrome is caused by a dominant parietal lobe lesion (angu- lar gyrus) and includes agraphia without alexia (patient can read but cannot write). Astereognosis is also caused by dominant parietal lobe lesions but is not part of Gerstmann’s syndrome.

Answer 261

A

A. Fibrous dysplasia
B. Osteoma
C. Eosinophilic granuloma
D. Giant cell tumor
E. Epidermoid

Epidermoids of the skull show a lytic defect with a scalloped, sclerotic rim. They are slow growing and rarely show malignant transformation.

Answer 262

A

A. Cochlear
B. Glossopharyngeal
C. Vagus
D. Accessory
E. Hypoglossal

Answer 263

A

A. Dreaming occurs.
B. Nightmares occur.
C. There is decreased duration with hypothyroidism.
D. Somnambulism occurs.
E. There is increased duration after sleep deprivation.

Nightmares occur during REM sleep; night terrors may occur in either stage 3 or 4 sleep. Stage 4 sleep is associated with delta waves.

Answer 264

A

A. dopamine.
B. norepinephrine.
C. serotonin.
D. dopamine and norepinephrine.
E. None of the above

Answer 265

A

A. Flexor digitorum profundus
B. Flexor pollicis longus
C. Pronator quadratus
D. All of the above
E. None of the above

Answer 266

A

A. Inferior petrosal sinus
B. Jugular bulb
C. Sigmoid sinus
D. Transverse sinus
E. PICA

A high-riding jugular bulb may be encountered during the drilling portion and should be tamponaded with hemostatic products and cottonoids.

Answer 267

A

A. Subforniceal organ
B. Subcommissural organ
C. Area postrema
D. All of the above
E. None of the above

The subcommissural organ is the only circumventricular organ with an intact blood–brain barrier (BBB).

Answer 268

A

A. penicillin.
B. captopril.
C. steroids.
D. All of the above
E. None of the above

Dysgeusias are particularly prevalent in the elderly and are often associated with the use of antihypertensives (e.g., captopril).

Answer 269

A

A. Observation
B. Surgical excision
C. Gamma knife
D. Partial surgical treatment
E. Lumbar drainage

Gamma knife treatment is the best mode of therapy for an AVM that is small- er than 3 cm and located in an eloquent area. The angiogram shows a small subcortical right parietal arteriovenous malformation with filling vessel aris- ing from a branch of the right middle cerebral artery. Venous drainage is not- ed into the upper sagittal sinus.

Answer 270

A

A. Cerebral atrophy
B. Wernicke’s encephalopathy
C. Central pontine myelinolysis
D. Foster Kennedy’s syndrome
E. Marchiafava–Bignami’s disease

Foster–Kennedy syndrome is usually caused by an olfactory groove or medial-third sphenoid wing tumor (usually meningioma). The classic triad is anosmia (ipsilateral), central scotoma (ipsilateral), and papilledema (contralateral).

Answer 271

A

A. Early Alzheimer’s disease
B. Pick’s disease
C. Creutzfeldt–Jakob Disease
D. Huntington’s disease
E. Diff use Lewy body dementia

Pick’s disease is characterized by severe focal atrophy commonly in the fron- tal and temporal lobes. This results in mental status and personality changes occurring in Pick’s patients. Pick bodies are positive for tau protein.

Answer 272

A

A. They are a triphasic potential.
B. They typically last 10–15 milliseconds.
C. They are caused by denervation.
D. They are seen with poliomyelitis, ALS, and peripheral nerve injury.
E. They may be associated with positive sharp waves.

Fibrillation potentials are triphasic and last 1–5 ms caused by the activity of one fiber.

Answer 273

A

A. stage 1 sleep.
B. stage 2 sleep.
C. stage 3 sleep.
D. stage 4 sleep.
E. REM sleep.

Sleep spindles (the burst described) and K complexes (sharp slow waves of high amplitude) are characteristic of stage 2 sleep.

Answer 274

A

A. Petrous bone
B. Hyperostosis
C. Anterior clinoid process
D. Posterior clinoid process
E. None of the above

The bony promontory seen in the picture is the posterior clinoid process and may be drilled carefully to expose the neck of the aneurysm.

Answer 275

A

A. a direct branch of the C5 root.
B. a branch from the middle trunk.
C. a branch from the posterior cord.
D. a branch from the superior trunk.
E. None of the above

The suprascapular nerve is trapped in the suprascapular notch. This nerve is the branch of the superior trunk. Atrophy of the supraspinatus and infraspi- natus can result.

Answer 276

A

A. III
B. IV
C. VI
D. VII
E. XII

The abducens nerve crosses the medial lemniscus on exiting the brainstem.

Answer 277

A

A. 50 mL/100 mg/min.
B. 50 mL/100 g/min.
C. 50 mL/mg/min.
D. 50 mL/g/min.
E. None of the above

The correct units are 50 mL/100 g/min.

Answer 278

A

A. Bell’s palsy
B. Familial dysautonomia
C. Raeder’s paratrigeminal syndrome
D. All of the above
E. None of the above

Answer 279

A

A. attention.
B. memory.
C. visuoconstructive ability.
D. executive function.
E. cognitive function.

Removal of frontal meningiomas may improve attentional functions. There are minimal differences in memory, visuoconstructive abilities, or executive functions.

Answer 280

A

A. causes decreased secretion of all pituitary hormones.
B. is independent from the hypophyseal portal system.
C. is independent from damage to hypothalamic neurons.
D. causes increased release of luteinizing hormone (LH).
E. causes increased secretion of prolactin (PRL).

The secretion of prolactin by lactotroph cells is inhibited by dopamine released by hypothalamic neurons.

Answer 281

A

A. there is increased activity of STN (subthalamic) neurons.
B. there is increased activity of SNpr (pars reticulata) neurons.
C. there is decreased activity of SNpr neurons.
D. there is increased activity of GPe (globus pallidus pars externa) neurons.
E. All of the above occur

The substantia nigra pars reticulata neurons related to saccadic eye move- ments decrease their activity during the saccade.

Answer 282

A

A. They have three to fi ve phases.
B. They last from 5 to 15 milliseconds.
C. They are associated with nerve fiber irritability.
D. They are not visible through the skin.
E. They may be associated with hypocalcemia, hypothermia, and nerve
entrapments.

Answer 283

A

A. Neural mechanisms regarding associative learning rarely are conserved between different species.
B. Calexcitin binds guanosine triphosphate (GTP), which is important in cell signaling.
C. At the endoplasmic reticulum membrane, it has been shown to bind to the ryanodine receptor with high affi nity.
D. Calexcitin directly inactivates voltage-dependent potassium currents.
E. It is a high-affi nity substrate for the -isozyme of protein kinase C (PKC).

Research with model systems of seemingly disparate species (i.e., marine snail and albino rat) suggest that neural mechanisms involved in associative learning may be highly conserved across species.

Answer 284

A

A. Anti-Hu antibodies and Lambert-Eaton myasthenic syndrome
B. Lambert-Eaton myasthenic syndrome and limbic encephalitis
C. Ectopic adrenocorticotropic hormone (ACTH) secretion
D. Syndrome of inappropriate antidiuretic hormone (SIADH)
E. All of the above

Answer 285

A

A. hypocalcemia.
B. hypokalemia.
C. hypothermia.
D. hypothyroidism.
E. subendocardial ischemia.

Hypothermia is characterized by J-point elevation.

Answer 286

A

A. Anterior encephaloceles
B. Parietal encephaloceles
C. Basal encephaloceles
D. Occipital encephaloceles
E. Encephaloceles without nasal deformities

Anterior encephaloceles are compatible with normal intelligence in the ma- jority of patients. Atretic encephaloceles also appear not to influence intel- lectual development and also have a low incidence of hydrocephalus.

Answer 287

A

A. TP53
B. PTEN
C. EGFR
D. All of the above
E. None of the above

Giant cell glioblastoma is shown in the slide. The hallmark of giant cell glio- blastoma is predominance on multinucleated giant cells and a high frequen- cy of the TP53 mutation.

Answer 288

A

A. Microvascular proliferation
B. Necrosis
C. Pseudopalisading
D. All of the above
E. None of the above

These features should not necessarily prompt the diagnosis of glioblastoma.

Answer 289

A

A. Angular gyrus
B. Supramarginal gyrus
C. Middle temporal gyrus
D. Superior parietal lobule
E. None of the above

The supramarginal gyrus is at the posterior reach of the sylvian fissure.

Answer 290

A

A. Medulla
B. Pons
C. Hypothalamus
D. Thalamus
E. Midbrain

Avellis’s syndrome is caused by a brainstem lesion that limits vagal innerva- tion unilaterally, resulting in ipsilateral paralysis of the vocal cord and soft palate and loss of sensitivity to pain and temperature in the contralateral leg, trunk, arm, and neck. This syndrome is also called ambiguospinothalamic paralysis.

Answer 291

A

A. glutamate agonist.
B. glutamate antagonist.
C. dopamine agonist.
D. GABA agonist.
E. GABA antagonist.

Bicuculline is a GABA-A antagonist. Muscimol is a GABA-A agonist. Ky- nurenate is a glutamate antagonist. Picrotoxin is a GABA inhibitor.

Answer 292

A

A. It may be associated with a footdrop.
**B. It is a condition of disordered myelination from decreased production of **
peripheral myelin protein 22 (PMP22).
C. It is the most common inherited peripheral neuropathy.
D. It is associated with a mutation on chromosome 17.
E. It is characterized by peroneal muscle atrophy.

There is increased production of PMP22 in Charcot–Marie–Tooth disease.

Answer 293

A

A. trigeminal motor nucleus and the spinal trigeminal tract.
B. dorsal aspect of the principle sensory nucleus and the spinal trigeminal
tract.
C. ventral aspect of the principle sensory nucleus and the spinal trigeminal
tract.
D. ventral aspect of the principle sensory nucleus and the mesencephalic
tract.
E. dorsal aspect of the principle sensory nucleus and the mesencephalic
tract.

Neurons in the spinal nucleus and in the ventral parts of the chief sensory nucleus give rise to the crossed ventral trigeminothalamic tract.

Answer 294

A

A. Motion is perceived by an object’s change of position on the retina.
B. The sensation of movement is known as the phi phenomenon.
C. Images that change positions more than 15 times per second are indistinguishable from continuous motion.
D. The motion system is disabled at rates below 100 Hz.
E. There is no physical process occurring on the retina that corresponds to
the perceived sensation of motion.

In stroboscopic illumination at flicker rates below 15 Hz, the motion system is disabled. This explains why nightclub dancers are seen as moving discon- tinuously under a strobe light.

Answer 295

A

A. Rubrospinal tract
B. Medial vestibulospinal tract
C. Tectospinal tract
D. All of the above
E. None of the above

The tectospinal tract decussates in the dorsal tegmental decussation. Tec- tospinal fibers originate from deeper layers of the superior colliculus and distribute to cervical cord levels. Rubrospinal fibers decussate in the ventral tegmental decussation.

Answer 296

A

A. It is the major predictor of later tumor recurrence.
B. It demands use of special instruments.
C. It will more likely result in anosmia postoperatively.
D. All of the above
E. None of the above

In the Royal Melbourne Hospital series of paranasal sinus involvement treat- ed by craniofacial resection, sphenoid sinus involvement was the major pre- dictor of later tumor recurrence.

Answer 297

A

A. Rods
B. Cones
C. Horizontal cells
D. Amacrine cells
E. Bipolar cells

Bipolar cells serve as interneurons between photoreceptor cells and ganglion cells.

Answer 298

A

A. GFAP.
B. S-100.
C. vimentin.
D. All of the above
E. None of the above

Answer 299

A

A. the straight sinus.
B. the vein of Galen.
C. the confl uence of sinuses.
D. the inferior sagittal sinus.
E. None of the above

Answer 300

A

A. It has been linked to severe defi ciency of myelin-specifi c lipids.
B. It is X-linked recessive in the classical form.
C. The connatal form (type II) is milder than the classical form.
D. It manifests as a “tigroid” pattern of perivascular myelin preservation on
MRI.
E. Rare instances of female cases have been described.

The connatal form (type II) is clinically more severe and symptoms begin in the neonatal period. Pelizaeus–Merzbacher disease (PMD) results from mu- tations affecting the gene for proteolipid protein (PLP).

Answer 301

A

A. Reticulocerebellar
B. Vestibulocerebellar
C. Trigeminocerebellar
D. Pontocerebellar tract
E. Olivocerebellar tract

The pontocerebellar tract passes to the cerebellum via the middle cerebellar peduncle. The ventral spinocerebellar tract and the tectocerebellar tract pass through the superior cerebellar peduncle.

Answer 302

A

A. The fl occulonodular lobe receives input from the vestibular nuclei.
B. The anterior lobe receives input from the spinocerebellar tracts.
C. The vermis sends fi bers to the VL thalamus and motor cortex.
D. The intermediate zone functions with posture, tone, and ipsilateral limb
movements.
E. A lesion of the interposed nuclei causes intention tremor.

The lateral zone (dentate) sends fibers to the VL thalamus and motor cortex (area 4). A lesion of the anterior lobe may cause slight hyperreflexia.

Answer 303

A

A. Dendrodendritic
B. Axodendritic
C. Axoaxonic
D. Axosomatic
E. Dendroaxonic

Dendrodendritic synapses have been found in the olfactory bulb and have been shown to be inhibitory; the granule cells processes make synaptic con- tacts with dendrites of mitral cells. Axodendritic synapses are excitatory. Axosomatic synapses are inhibitory, and a classic example is the cerebellar basket cell contacting the Purkinje cell.

Answer 304

A

A. It is a small cell with a compact dendritic tree.
B. It represents a minority of the total ganglion cell number.
C. It projects to layer 4C in the striate cortex.
D. It is involved with color processing.
E. It has low contrast sensitivity and high acuity

The parvocellular system of the dorsal lateral geniculate nucleus makes up about 80% of the total ganglion cell number.

Answer 305

A

A. It manifests as a decrease in end tidal CO2.
B. Air should be aspirated from the right atrium if it occurs.
C. The patient should be placed in the left lateral decubitus position.
D. The head should be lowered if possible.
E. End tidal CO2 changes cannot precede precordial Doppler changes.

During a neurosurgical procedure, a sudden decrease in end tidal CO2 sug- gests venous air embolus and may even precede the appreciation of changes by the precordial Doppler.

Answer 306

A

A. caudate vein.
B. septal vein.
C. basal vein of Rosenthal.
D. internal cerebral vein.
E. thalamostriate vein.

These structures run in the floor of the body of the lateral ventricle.

Answer 307

A

A. Median nerve, brachial artery, biceps brachii tendon, radial nerve
B. Median nerve, biceps brachii tendon, radial nerve, brachial artery
C. Biceps brachii tendon, median nerve, radial nerve, brachial artery
D. Brachial artery, biceps brachii tendon, radial nerve, median nerve
E. None of the above

The contents of the cubital fossa from medial to lateral are the median nerve, brachial artery, biceps brachii tendon, and radial nerve.

Answer 308

A

A. Pectoralis major
B. Subscapularis
C. Teres major
D. Teres minor
E. Latissimus dorsi

The teres minor rotates the arm laterally.

Answer 309

A

A. Vein of Galen
B. Basal vein of Rosenthal
C. Internal cerebral vein
D. Thalamostriate vein
E. Caudate vein

The internal cerebral vein position can be confirmed by superimposing the angiogram of the medial posterior choroidal artery with the venous phase. The internal cerebral vein and the medial posterior choroidal artery occupy the same position when the arterial and venous phase are superimposed. Both of these structures course within the cistern of the velum interpositum.

Answer 310

A

A. Basilar
B. Anterior spinal
C. Vertebral
D. PICA
E. AICA

Answer 311

A

A. excitatory control of cardiac function.
B. inhibitory control of cardiac function.
C. excitatory control of respiratory function.
D. inhibitory control of respiratory function.
E. None of the above

The Botzinger complex is the principle source of reciprocal inhibition in the respiratory network. It comprises a cluster of cells at the rostral-most tip of the ventral respiratory group.

Answer 312

A

A. Superior trunk
B. Medial trunk
C. Lateral cord
D. Posterior cord
E. Medial cord

The posterior cord gives rise to the upper subscapular, lower subscapular, and thoracodorsal nerves. The latissimus dorsi is innervated by the thoracodorsal nerve. The subscapularis muscle is innervated by the upper and lower sub- scapular nerve. The teres major is innervated by the lower subscapular nerve.

Answer 313

A

A. The majority of adults with this disease present with ischemia.
B. The age of onset of symptoms displays a bimodal distribution.
C. It is of unknown etiology.
D. It involves progressive stenosis of the supraclinoid carotid arteries with
the concomitant formation of rich collaterals at the skull base.
E. It is associated with Down syndrome and neurofi bromatosis.

The vast majority of children present with ischemic symptoms (transient ischemic attacks (TIAs), extremity weakness), whereas adults typically pres- ent with hemorrhage.

Answer 314

A

A. It is eff ective in generalized tonicoclonic seizures.

B. It is ~90% protein bound.
C. It has a long half-life.
D. It may be associated with platelet dysfunction.
E. It may result in liver dysfunction.

Valproic acid has a short half-life (~ 8 hours). Association with platelet dys- function should alert the surgeon to the possibility of bleeding problems, especially in epilepsy cases.

Answer 315

A

A. Enflurane
B. Isoflurane
C. Nitrous oxide
D. Halothane
E. Ketamine

Isoflurane allows patients to emerge from anesthesia faster, and there is less hepatic effect from this agent. In addition, isoflurane produces the least in- crease in cerebral blood flow (CBF) of inhalational anesthetics.

Answer 316

A

A. the frontal horn.
B. the temporal horn.
C. the atrium.
D. the occipital horn.
E. None of the above

The glomus is a prominent tuft of choroid plexus found in the atrium.

Answer 317

A

A. Axillary, musculocutaneous
B. Median, musculocutaneous
C. Axillary, radial, ulnar
D. Median, radial, ulnar
E. Median, radial

The axillary nerve passes posteriorly around the surgical neck of the humer- us. The radial nerve lies in the radial groove of the middle of the shaft of the humerus. The ulnar nerve passes behind the medial epicondyle. All three of these nerves are susceptible to humerus fractures since they lie in close con- tact with bone.

Answer 318

A

A. precentral gyrus.
B. postcentral gyrus.
C. premotor cortex.
D. prefrontal cortex.
E. cingulated gyrus.

The premotor area plays a role in programming and sequencing learned
complex movements.

Answer 319

A

A. Vein of Galen
B. Basal vein of Rosenthal
C. Internal cerebral vein
D. Straight sinus
E. Precentral cerebellar vein

Answer 320

A

A. 5 Hz
B. 10 Hz
C. 15 Hz
D. 20 Hz
E. 25 Hz

Theta activity has a frequency of 4–7 Hz. Other common electroenceph- alographic (EEG) rhythms are delta (0–3 Hz), alpha (8–13 Hz), and beta (> 13 Hz).

Answer 321

A

A. Motor nucleus of V (trigeminal)
B. Mesencephalic nucleus of V
C. Sensory nucleus of V
D. Red nucleus
E. Locus ceruleus

The mesencephalic nucleus of the trigeminal nerve has pseudounipolar neu- rons. The mesencephalic nucleus extends from the pons to the upper mid- brain. It receives input from muscle spindles and pressure receptors.

Answer 322

A

A. fi rst-order neurons of the ventral spinocerebellar tract.
B. second-order neurons of the ventral spinocerebellar tract.
C. fi rst-order neurons of the dorsal spinocerebellar tract.
D. second-order neurons of the dorsal spinocerebellar tract.
E. None of the above

These second-order neurons will give rise to axons that enter the cerebellum via the superior cerebellar peduncle. The ventral spinocerebellar tract con- veys efference copies of motor commands for the lower extremities.

Answer 323

A

A. represent corticotrope cells.
B. stain purple after periodic acid-Schiff (PAS) staining.
C. represent somatotrope cells.
D. lack cytoplasmic granules.
E. can only be acidophils or basophils

Chromophobic cells lack cytoplasmic granules. They represent acidophil or basophil cells after the release of hormone-containing granules. They have no stain reaction after PAS stain.

Answer 324

A

A. anterior resection.
B. posterior resection.
C. lateral resection.
D. medial resection.
E. None of the above

The extent of mesiobasal resection determines the outcome after temporal lobectomy for intractable complex partial seizures.

Answer 325

A

A. Huntington’s chorea.
B. chorea gravidarum.
C. senile chorea.
D. hysterical chorea.
E. Sydenham’s chorea.

Sydenham’s chorea is the most common type of chorea. Also known as St. Vi- tus’s dance, this chorea occurs mainly in young females after a bout of rheu- matic fever.

Answer 326

A

A. myopathy.
B. susceptibility to infection.
C. posterior subcapsular cataracts.
D. All of the above
E. None of the above

This is decadron. A postoperative course of an H2-receptor blocker is indicat- ed for patients on glucocorticoid treatment.

Answer 327

A

A. The ulnar artery is superfi cial to it.
B. The median nerve is deep to it.
C. The ulnar nerve is superfi cial to it.
D. All of the above
E. None of the above

Answer 328

A

A. Thalamotomy
B. Ventralis intermedius stimulation
C. GPi stimulation
D. Any of the above
E. None of the above

Ventralis intermedius (Vim) stimulation is the procedure of choice when contralateral thalamotomy has been performed or is anticipated.

Answer 329

A

A. meningioma.
B. arteriovenous malformations.
C. anaplastic astrocytoma.
D. ependymomas.
E. None of the above

Temozolomide (TMZ) is an orally administered chemotherapeutic (alkyl- ating) agent with minimal side effects that readily crosses the blood–brain barrier and is approved for treating anaplastic astrocytomas.

Answer 330

A

A. polyneuropathy.
B. cervical radiculopathy.
C. myopathy.
D. S1 radiculopathy.
E. median nerve compression

The H-reflex is a submaximal stimulation of mixed motor-sensory nerves, not enough to cause a direct motor response. The H-reflex is the electrical representation of the tendon reflex circuit.

Answer 331

A

A. Lipofuscin accumulation
B. Lewy bodies
C. Marinesco bodies
D. Alzheimer changes
E. Colloid inclusions

The most common and pronounced aging effect on the brain is cell loss.

Answer 332

A

A. Dorsal column
B. Spinospinal
C. Ventral spinocerebellar
D. Dorsal spinocerebellar
E. Spinothalamic

Stereognosis is an important function of the dorsal column–medial lemnis-
cal system.

Answer 333

A

A. Pressure gradients between left and right sides of the brain and supra- and
infratentorial compartments may be present.
B. The incidence of hemorrhage after insertion is about 1%.
C. Irrigating the tubing decreases the contamination rate of ventricular
catheters.
D. Decreased intracranial compliance is suggested when the “b wavelet” is
greater than the “a wavelet.”
E. There is no clear consensus as to whether to use prophylactic antibiotics.

Irrigation of fluid-coupled monitoring systems increases the infection rate nearly threefold. Thus irrigation, if necessary, should be performed infre- quently and with exquisite sterile technique.

Answer 334

A

A. In the pyramidal decussation, arm areas of cortex cross rostral to those
that arise from leg areas.
B. It receives contribution from somatomotor cortex, prefrontal regions, and
parietal areas.
C. Glutamate is present in cortical eff erent fi bers that project to the spinal
cord.
D. Leg fi bers are lateral to arm fi bers at most levels of this particular tract.
E. Area 4 and postcentral gyrus fi bers terminate in the same spinal cord
lamina.

Area 4 fibers terminate in laminae VI–IX, whereas fibers starting in laminae IV and V project to the postcentral gyrus via the spino-thalamic tract. The anterior corticospinal tract is an uncrossed tract in the (medial) ventral cord and terminates on lamina VII.

Answer 335

A

A. The inferior parietal lobule
B. Broca’s area
C. Wernicke’s area
D. The primary auditory cortex
E. The paracentral lobule

The paracentral lobule is supplied by branches from the anterior cerebral artery.

Answer 336

A

A. the genu of the corpus callosum.
B. the cingulate gyrus.
C. the pericallosal artery.
D. the splenium of the corpus callosum.
E. None of the above

Answer 337

A

A. 13 degrees.
B. 30 degrees.
C. 100 degrees.
D. 130 degrees.
E. 180 degrees.

Answer 338

A

A. Anteromedial
B. Anterolateral
C. Posteromedial
D. Posterolateral
E. None of the above

The sensorimotor GPi is located in the posterolateral part of the nucleus.

Answer 339

A

A. The majority of these lesions arise from a ventral nerve root.
B. 10 to 15% extend through the dural root sleeve.
C. The fourth through sixth decades represent the peak incidence of
occurrence.
D. These masses are typically described as smooth globoid and do not produce enlargement of the nerve.
E. They are suspended eccentrically from the nerve root with a discrete
attachment.

The lesion represents a nerve root schwannoma. The majority of these arise from a dorsal nerve root. Ten to 15% extend through the dural root sleeve. The fourth through sixth decades represent the peak incidence of occur- rence. Schwannomas are typically described as smooth globoid and do not produce enlargement of the nerve but are suspended eccentrically from it with a discrete attachment.

Answer 340

A

A. Anaerobic
B. Fast
C. Stain dark with ATPase at pH 9.4
D. Are found in red muscle
E. Have few mitochondria

Type I fibers are characterized by slow contraction times and a high resistance to fatigue. Structurally, they have a small motor neuron and fiber diameter, a high mitochondrial and capillary density, and a high myoglobin content.

Answer 341

A

A. Pick bodies
B. Lewy bodies
C. Cowdry type B bodies
D. Bunina bodies
E. Lafora bodies

Cowdry type A inclusions are intranuclear and are seen with cytomegalovi- rus, herpes, and subacute sclerosing panencephalitis (SSPE). Cowdry type B inclusions are intranuclear and are seen in acute poliovirus. The others listed are intracytoplasmic inclusions. Lafora bodies are seen in myoclonic epilep- sy. Bunina bodies are seen in amyotrophic lateral sclerosis (ALS).

Answer 342

A

A. Lateral spinothalamic
B. Ventral spinocerebellar
C. Ventral corticospinal
D. Dorsal spinocerebellar
E. Ventral spinothalamic

The dorsal spinocerebellar is an uncrossed tract.

Answer 343

A

A. Nystagmus is horizontal and ipsilateral to the aff ected side.
B. Nystagmus is vertical.
C. Falling and past-pointing are contralateral.
D. Nystagmus is contralateral to the aff ected side.
E. None of the above

Nystagmus in Ménière’s disease is horizontal and contralateral to the affect-
ed side. Past-pointing and falling occur toward the affected side.

Answer 344

A

A. Pulvinar
B. Anterior nucleus
C. Centromedian nucleus
D. VA nucleus
E. VL nucleus

The pulvinar has reciprocal connections with the inferior parietal lobule.

Answer 345

A

A. anterior commissure.
B. hippocampal commissure.
C. body of the corpus callosum.
D. genu of the corpus callosum.
E. splenium of the corpus callosum.

Answer 346

A

A. anterosuperiorly.
B. posterosuperiorly.
C. anteroinferiorly.
D. posteroinferiorly.
E. None of the above

Pineal tumors usually lie between the precentral cerebellar vein and the vein of Galen. The precentral cerebellar vein is usually displaced posterosuperior- ly. This vein may be sacrificed if necessary.

Answer 347

A

A. Occipital condyle
B. Inion
C. Pharyngeal tubercle
D. Pituitary gland
E. Sphenoid sinus

The pharyngeal tubercle is found in line with the vomer and foramen mag- num at the cranial base.

Answer 348

A

A. Posterior inferior cerebellar artery
B. Posterior cerebral artery
C. Anterior choroidal artery
D. All of the above
E. None of the above

The anterior choroidal and lateral posterior choroidal supply the lateral ven- tricle. The medial posterior choroidal supplies the choroid plexus of the third ventricle. The posterior inferior cerebellar artery (PICA) supplies the choroid plexus of the third ventricle.

Answer 349

A

A. Asterixis
B. Slowing of the EEG waves
C. Increased levels of ammonia
D. Increased levels of GABA neurotransmitter
E. Decreased levels of glutamate

The liver damage causes the levels of ammonia to rise because it is not converted to urea; this may lead to increased production of GABA. Glutamate is not involved.

Answer 350

A

A. Serum ceruloplasmin is low.
B. Urinary copper is increased.
C. The gene locus is on chromosome 13.
D. Inheritance is autosomal dominant.
E. Early in the course of the disease, liver biopsy shows a high copper
content.

Wilson’s disease (hepatolenticular degeneration) is a familial metabolic dis- ease transmitted as an autosomal recessive trait. The abnormal gene has been assigned to the esterase D locus on chromosome 13.

Answer 351

A

A. They serve as guides for migrating granular cell neurons during
development.
B. They have cell bodies located in the molecular layer of the cerebellar
cortex.
C. They undergo reactive gliosis adjacent to infarcts.
D. They extend long cytoplasmic processes through the molecular layer to
the subpial surface.
E. They are inconspicuous until stimulated by local damage.

Bergmann glia have cell bodies located in the Purkinje layer of the cerebellar cortex.

Answer 352

A

A. The signs are frequently unilateral.
B. It classically involves spinal roots inferior to L3.
C. It may result in profound motor defects.
D. It may result in urinary or fecal incontinence.
E. It usually results in a Babinski sign

This is a lower motor neuron lesion and Babinski’s sign would not be expected.

Answer 353

A

A. the kinetic labyrinth.
B. the ampullae.
C. the static labyrinth.
D. the cochlear duct.
E. None of the abov

The static labyrinth consists of the utricle and saccule. The vestibule is a cen- tral cavity of the inner ear that contains the saccule and utricle.

Answer 354

A

A. VA
B. VL
C. VPL
D. VPM
E. None of the above

The ventral posteromedial (VPM) nucleus receives taste input via the ipsilat- eral central tegmental tract. The VPM nucleus receives sensory input from the head and oral cavity.

Answer 355

A

A. a lateral suboccipital retrosigmoid approach.
B. a combined subtemporal presigmoid approach.
C. an infratentorial supracerebellar approach.
D. a suboccipital transtentorial approach.
E. a pterional approach

The lateral suboccipital retrosigmoid approach is best used for lateral tento- rial notch meningiomas that extend infratentorially.

Answer 356

A

A. 6 years.
B. 12 years.
C. 18 years.
D. 26 years.
E. 30 years.

Calcifications are likely to be abnormal if encountered in children younger than 6 years. The incidence of pineal calcification is at most 40% by the age of 18.

Answer 357

A

A. Anterior longitudinal ligament
B. Posterior longitudinal ligament
C. Alar ligament
D. Transverse ligament
E. None of the above

The anterior longitudinal ligament attaches the dens to the anterior tubercle of the atlas. The transverse ligament of the atlas is posterior to the dens. The apical and alar ligaments attach the dens to the foramen magnum.

Answer 358

A

A. third ventricle.
B. fourth ventricle.
C. left lateral ventricle.
D. right lateral ventricle.
E. septum pellucidum.

The most frequent site of subependymoma is the fourth ventricle (50–60% of cases), followed by the lateral ventricles (30–40%). Less common sites are the third ventricle and septum pellucidum.

Answer 359

A

A. the anterior commissure.
B. the fornix.
C. the rostrum of the corpus callosum.
D. the mammillary body.
E. None of the above

The lamina terminalis fills the interval between the anterior commissure and the optic chiasm.

Answer 360

A

A. both eyes being deviated to the right at rest.
B. both eyes being deviated to the left at rest.
C. the right eye being “down-and-out.”
D. the patient being unable to look upward.
E. both eyes being deviated upward.

Damage to the right frontal eye field (area 8) results in deviation of the eyes to the right.

Answer 361

A

A. oligodendroglioma.
B. low-grade astrocytoma.
C. pleomorphic xanthoastrocytoma.
D. choroid plexus papilloma.
E. schwannoma.

Choroid plexus papillomas frequently display immunopositivity for tran- sthyretin (prealbumin) and S-100.

Answer 362

A

A. 7 mL/100 g/min.
B. 16 mL/100 g/min.
C. 30 mL/100 g/min.
D. 35 mL/100 g/min.
E. 45 mL/100 g/min.

Between 15 and 20 mL/100 g/min cortical evoked responses are lost and the (EEG) becomes isoelectric, but the neurons remain viable and are described as “idling.” At about 30 mL/100 g/min, the patient loses consciousness.

Answer 363

A

A. It arises from the ipsilateral Deiter’s nucleus.
B. It is located in the lateral pontine tegmentum.
C. It crosses the midline with MLF fi bers.
D. It facilitates extensor muscle tone in the antigravity muscles.
E. It is found at all spinal cord levels

The lateral vestibulospinal tract is an uncrossed tract.

Answer 364

A

A. Anterior nucleus
B. Centromedian nucleus
C. Pulvinar
D. VA
E. Mediodorsal nucleus

Lesions of the mediodorsal nucleus are found in patients with the Korsakoff amnestic state.

Answer 365

A

A. III
B. IV
C. V
D. VI
E. VII

The trochlear nerve should be identified before transecting the tentorium.

Answer 366

A

A. They are the most common parapineal neoplasm.
B. They occur predominantly in males.
C. They commonly occur at around age 30 and above.
D. They are fi ve to ten times more likely in Japan.
E. They are infi ltrated by T cell lymphocytes

Germinomas commonly occur in males in the first 3 decades.

Answer 367

A

A. It is sensitive to steroids.
B. It may mimic multiple sclerosis.
C. It can involve cranial nerves.
D. It is characterized pathologically by caseating granulomas.
E. Leptomeningeal involvement is common

Pathologically central nervous system (CNS) sarcoid is characterized by non- caseating granulomas.

Answer 368

A

A. Choroid plexus tumor
B. Gliosarcoma
C. Cystic astrocytoma
D. Oligodendroglioma
E. Glioblastoma multiforme

Although other tumors may be more common after 1 year of life, choroid plexus tumors are the most common tumor in the first year of life.

Answer 369

A

A. Frontal lobe
B. Temporal lobe
C. Parietal lobe
D. Occipital lobe
E. Basal ganglia

A “square” ACA shift is usually caused by a holotemporal mass.

Answer 370

A

A. upper midbrain.
B. lower midbrain.
C. upper pons.
D. middle pons.
E. lower pons.

Answer 371

A

A. Obex
B. Subcommissural organ
C. Median eminence
D. Organum vasculosum of the lamina terminalis
E. Area postrema

The obex is the caudal apex of the rhomboid fossa and marks the beginning of the “open medulla.”

Answer 372

A

A. Pericallosal
B. Anterior communicating
C. Posterior communicating
D. Middle cerebral
E. Superior hypophyseal

Hyponatremia (Na < 130) can occur in up to 30% of ruptured anterior com- municating artery aneurysms due to the local proximity of key perforators that supply the anterior hypothalamic nuclei.

Answer 373

A

A. It is a branch of the vertebral artery.
B. It supplies the vestibular nuclei in the medulla.
C. It supplies the medial lemniscus in the medulla.
D. It supplies the inferior cerebellar peduncle.
E. It supplies the lateral spinothalamic tract.

Answer 374

A

A. is located lateral to the fovea.
B. contains myelinated axons from the retinal ganglion cell layer of the
retina.
C. contains only cones.
D. All of the above
E. None of the above

The optic disc (optic papilla) is located 3.5 mm nasal to the fovea centralis. It contains unmyelinated axons from the ganglion cell layer of the retina. The optic disc is the blind spot (contains neither rods nor cones).

Answer 375

A

A. Rectus capitis posterior major
B. Superior obliquus capitis
C. Inferior obliquus capitis
D. Longissimus capitis
E. None of the above

The inferior obliquus capitis muscle forms a common border of the superior and inferior suboccipital triangles. The lateral borders of both triangles meet at the transverse process of the atlas, which is located 1 cm below the mas- toid tip.

Answer 376

A

A. the trigeminal nerve.
B. the abducens nerve.
C. the facial nerve.
D. All of the above
E. None of the above

The facial nerve needs to be identified medially close to the brain stem and followed laterally.

Answer 377

A

A. The great majority of spinal meningiomas occur in females.
B. The most common presenting symptom is pain.
C. Plain film calcification is often seen.
D. Inversion recovery sequences and use of gadolinium increase detection
sensitivity.
E. Calcospheres may be seen.

Plain film calcification is rarely seen. Calcospheres are also known as psam- moma bodies.

Answer 378

A

A. Teres minor
B. Teres major
C. Latissimus dorsi
D. Subscapularis
E. Infraspinatus

The infraspinatus is innervated by the suprascapular nerve, which originates from the upper trunk of the brachial plexus. The subscapularis is innervated by the upper and lower subscapular nerves. The teres major is innervated by the lower subscapular nerve. The latissimus dorsi is innervated by the thora- codorsal nerve. The teres minor is innervated by the axillary nerve.

Answer 379

A

A. Time of development is directly related to the rate of turnover of the cells.
B. Cell loss after radiation occurs in connection with the cell division.
C. Time of development is directly dependent on the radiation dose.
D. Slowly proliferating tissue like CNS may take years to show the eff ects.
E. All of the above statements are true

The time of development of effects of radiation is dose independent.

Answer 380

A

A. Leigh’s disease
B. MERFF
C. MELAS
D. Kearns–Sayre’s syndrome
E. Kawasaki’s disease

Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) is a condition that affects many of the body’s systems, particularly the brain and nervous system (encephalo-) and muscles (myopathy). MERRF stands for “myoclonic epilepsy with ragged-red fibers.” Kawasaki disease is a condition that causes inflammation in the walls of medium-sized arteries throughout the body, including the coronary arteries, which supply blood to the heart muscle. Kawasaki disease is also called mucocutaneous lymph node syndrome because it also affects lymph nodes, skin, and the mucous mem- branes inside the mouth, nose and throat. The etiology of Kawasaki disease is unknown. Most of the epidemiologic and immunologic evidence indicates that the causative agent is probably infectious. However, autoimmune reac- tions and genetic predisposition are suggested as possible etiologic factors.

Answer 381

A

A. Loss of heterozygosity (LOH) at 1p and 19q in oligodendrogliomas
B. LOH at 22 in ependymomas
C. LOH at 17 in astrocytomas
D. Monosomy of 22 in ATRT
E. Amplification of N-myc in glioblastoma

Amplification of epidermal growth factor (EGF) occurs in glioblastoma. Dou- ble minutes (cytogenetic evidence of gene amplification) of N-myc occurs in medulloblastoma.

Answer 382

A

A. myocardial infarction within the last 6 months.
B. age greater than 75.
C. more than fi ve ventricular ectopic beats per minute.
D. smoking more than one pack of cigarettes a day.
E. being hepatitis C positive

The Goldman cardiac risk score for noncardiac surgery indicates that a recent myocardial infarction (MI) is a contraindication to elective surgery.

Answer 383

A

A. Dorsal spinocerebellar
B. Cuneocerebellar
C. Fastigiovestibular
D. Olivocerebellar
E. Vestibulocerebellar

The fastigiovestibular tract is an efferent pathway that passes through the superior cerebellar peduncle (SCP) (uncinate fasciculus of the SCP). The jux- tarestiform body is a component of the inferior cerebellar peduncle and con- tains afferent (vestibulocerebellar) and efferent (cerebellovestibular) fibers.

Answer 384

A

A. unilateral destruction of the cuneus.
B. bilateral destruction of both cunei.
C. unilateral destruction of the lingual gyrus.
D. bilateral destruction of both lingual gyri.
E. None of the above

Bilateral destruction of both cunei results in a lower altitudinal hemianopia.

Answer 385

A

A. Temporary clipping of the carotid in the neck
B. Lumbar drainage
C. Preoperative use of steroids
D. Keeping the patient intubated until surgery
E. Minimal retraction

A posterior communicating artery aneurysm is prone to rupture with retration on the temporal lobe.

Answer 386

A

A. It is an indication of the activity peripheral to the tumor.
B. It is easier to detect than the other waves.
C. Wave 5 is an accurate predictor of hearing postoperatively regardless
of N1.
D. All of the above
E. None of the above

Wave 5 is an indication of auditory nerve activity central to the tumor. It is easier to detect than the other waves. Wave 5 is generated in the brainstem. When used with N1 (monitors action potential of the auditory nerve), it is useful for predicting postoperative hearing function.

Answer 387

A

A. Axons are intact.
B. Unidentifi ed bright objects (UBOs) may be seen on MRI.
C. Active lesions show contrast enhancement.
D. Initial symptoms are referable to motor function.
E. About 10 percent have a positive family history.

The most common symptom at initial presentation is referable to sensation.

Answer 388

A

A. Anterior thalamus
B. Cingulated gyrus
C. Fornix
D. Hippocampus
E. Dorsomedial thalamus

The dorsomedial thalamus is a part of the basolateral circuit. The basolateral circuit passes from the orbitofrontal cortex to the anterior temporal cortex via the uncinate fasciculus, then to the amygdala and the dorsomedial nucle- us of the thalamus, and back to the orbitofrontal cortex via a thalamofrontal radiation. The circuit of Papez passes from the septal region via the cingulat- ed bundle to the hippocampus, then via the fornix to the mammillary bodies via the mammillothalamic tract to the anterior thalamus, then from the an- terior thalamus back to the cingulum.

Answer 389

A

A. White matter degeneration aff ecting mostly subcortical U-fi bers
B. Bilateral spongiform degeneration of the thalamus and basal ganglia
C. Degeneration of the peripheral nerves
D. Degeneration of the spinal cord
E. Degeneration of the brainstem

White matter degeneration of the subcortical U-fibers. This is a feature of Canavan’s disease, which is a different metabolic disease with the same in- heritance pattern and is caused by a deficiency of the enzyme N-acetyl-as- partoacylase.

Answer 390

A

A. Brodmann area 40.
B. Brodmann area 41.
C. Brodmann area 42.
D. Brodmann area 43.
E. Brodmann area 44.

Broca’s aphasia results from damage to Brodmann area 44 (inferior frontal gyrus). The most common cause of expressive aphasia is stroke. The most effective pharmacological treatments are piracetam and amphetamine.

Answer 391

A

A. adrenoleukodystrophy.
B. Canavan’s disease.
C. Alexander’s disease.
D. Krabbe’s disease.
E. metachromatic leukodystrophy

Canavan’s disease is associated with a point mutation of aspartoacylase 2 leading to elevated levels of N-acetylaspartic acid (NAA). It is a progres- sive, fatal neurological disorder that is caused by this mutation, which affects myelin.

Answer 392

A

A. hemophilia A.
B. factor V defi ciency.
C. aspirin.
D. heparin.
E. vitamin K defi ciency

Antiplatelet drugs are the most common cause of platelet disorders leading to excessive bleeding at surgery. Excessive bleeding in surgery can usually be seen early at skin incision and during initial dissection. If the surgeon believes that the unexpected excessive bleeding will pose a risk to the patient, it is ad- visable to abort the procedure, obtain a hematology consult, and proceed with surgery on another day. If the surgeon decides that the bleeding is not going to pose a threat to the patient, it is advisable to leave a small drain under only light bulb suction (not fully compressed suction), to use a pressure dressing at the end of the case, and to obtain a hematocrit after the case.

Answer 393

A

A. Poxvirus
B. Picornavirus
C. Paramyxovirus
D. Reovirus
E. Rhabdovirus

Poxvirus is a DNA virus. Viral meningitis occurs in up to 50% of paramyx- ovirus infections (mumps). Rabies (rhabdovirus) targets the limbic tissue. DNA viruses cause SSPE, PML (papovavirus), and herpes encephalitis. RNA viruses are implicated in meningitis, AIDS, Ebola, severe acute respiratory syndrome (SARS), West Nile, and polio. Herpes simplex encephalitis (HSE) is the only CNS viral infection whose course and outcome are improved by specific antiviral therapy (acyclovir). HSE can lie dormant in the ganglion of the trigeminal nerve causing trigeminal neuralgia. If acyclovir is not helpful, radiosurgical treatment of the trigeminal nerve may be indicated.

Answer 394

A

A. radiotherapy.
B. chemotherapy.
C. gene therapy.
D. photochemotherapy.
E. None of the above

Hematoporphyrin derivative is an agent that is capable of photosensitizing malignant tumor cells. Other photosensitizers include rhodamine, acridine orange, phthalocyanines, and pyrilium derivatives.

Answer 395

A

A. I.
B. II.
C. III.
D. IV.
E. V

The cranial nerve most sensitive to radiation is the optic nerve and the chi- asm, with a single fraction dose tolerance of 8 Gy. Other cranial nerves can be affected from radiation in order of frequency: XII, XI, X, V, and VI. The recurrent laryngeal nerve can be injured after radiation therapy for breast or lung cancers; therefore, in anterior cervical discectomy and fusion (ACDF) cases, patients with a history of radiation in these areas should be briefed on the higher risk of hoarseness and vocal changes after surgery.

Answer 396

A

A. the junction of the transverse and sigmoid sinuses.
B. the jugular bulb.
C. AICA.
D. All of the above
E. None of the above

The junction of the transverse and sigmoid sinuses is usually located 1–1.5 cm rostral to the mastoid emissary vein. In this photograph (reprinted with permis- sion from The American Society of Neuroradiology) the mastoid emissary vein is labeled n, the transverse sinus is labeled b, and the sigmoid sinus is labeled c. Profuse bleeding can be seen in dissections near this vein as well as other veins in the cerebellar area. It is important for the surgeon to have hemoclips, hemo- static packing agents, and BioGlue (CryoLife)/DuraSeal (Optimus Medical) ready in the room should the need arise in any posterior fossa surgery.

Answer 397

A

A. the substantia gelatinosa.
B. the nucleus proprius.
C. the zona intermedia.
D. All of the above
E. None of the above

The Rexed laminae is the system of ten layers of gray matter (I–X) named after Swedish neuroscientist Bror Rexed in the 1950s. (Figure from THIEME Atlas of Anatomy, Head and Neuroanatomy, © Thieme 2007, Illustration by Markus Voll.)

Answer 398

A

A. Mossy fi bers terminal
B. Golgi cell dendrite
C. Granule cell dendrite
D. Purkinje cell
E. Golgi cell axon termina

Cerebellar glomeruli are small, intertwined nerve fiber terminals in the granular layer of the cerebellar cortex. Glomeruli contain synaptic connec- tions that contain axons of incoming mossy fibers, axons and dendrites of Golgi type II cells, and dendrites of granule cells. Purkinje cells are not part of the glomerulus. The cerebellar glomeruli are the first stop for afferent nerve fibers entering the cerebellum.

Answer 399

A

A. cellular apoptosis.
B. endothelial cell proliferation.
C. demyelination of the nerve fi bers.
D. diff use vasculitis.
E. focal white matter necrosis.

Focal white matter necrosis is the most common histological evidence of late radiation-related CNS injury.

Answer 400

A

A. Cervical
B. Thoracic
C. Lumbar
D. Sacral
E. None of the above

Sacral. The gray matter changes shape throughout the spinal cord depending on the neural requirements of a given region.

Answer 401

A

A. MERRF
B. CADASIL
C. MPS IV
D. HHT
E. VHL

Cerebral autosomal dominant arteriopathy with subcortical infarcts (CA- DASIL) leads to subcortical ischemic damage, myelin loss, lacunar infarcts, and gliosis. Ischemic strokes are the most frequent presentation of CADASIL where the underlying pathology is progressive degeneration of the smooth muscles cells in blood vessels.

Answer 402

A

A. hyperglycemia.
B. psychosis.
C. exacerbation of peptic ulcer.
D. aseptic necrosis.
E. skin rash.

Exacerbation of peptic ulcer is the most common side effect of high-dose dexamethasone. A short course (e.g., ≤ 4 days) of steroids does not need to be tapered. Longer courses of steroids should be tapered gradually.

Answer 403

A

A. Patients rarely complain of headache.
B. Nausea, vomiting, mental status changes, and cranial nerve palsies are
features.
C. It is caused by an encapsulated budding yeast.
D. In some communities, it is more common than toxoplasmosis as a cause of
presenting neurological illness associated with HIV infection.
E. Infection occurs by the inhalation of organisms resulting in a primary
pulmonary focus of infection

Headache is almost universally noted in patients with cryptococcal menin- gitis. Poor prognosis of cryptococcal meningitis is seen with positive India ink stain, low CSF leukocyte count, a positive blood culture, presence of C. neoformans at extraneural sites, high CSF cryptococcal antigen titers, CSF hypoglycorrhachia, and an increased CSF opening pressure. Pharmacological treatment involves amphotericin B plus flucytosine.

Answer 404

A

A. 1%
B. 15%
C. 45%
D. 65%
E. 85%

Since over 85% of cerebrospinal fluid leaks from basilar skull fractures will resolve spontaneously, the primary approach is expectant observation. Prophylactic antibiotics have not been shown to decrease the risk of menin- gitis and are not recommended. CSF diversion with lumboperitoneal shunts may be used for refractory cases.

Answer 405

A

A. PRL.
B. ACTH.
C. TSH.
D. All of the above
E. None of the above

Pituitary tumors that secrete thyroid-stimulating hormone (TSH) also fre- quently co-secrete the glycoprotein hormone alpha-subunit. An alpha-sub- unit:TSH ratio of > 1 favors the diagnosis of TSH-secreting adenoma. TSH is a glycoprotein and consists of two subunits, alpha and beta. The alpha sub- unit is identical to that of human chorionic gonadotropin (hCG), luteinizing hormone (LH), and follicle-stimulating hormone (FSH). The beta subunit is unique to TSH and determines its receptor specificity.

Answer 406

A

A. the superior semicircular canal.
B. the lateral semicircular canal.
C. the posterior semicircular canal.
D. All of the above
E. None of the above

The superior (anterior) semicircular canal is identified by the arcuate emi- nence at the base of the skull.

Answer 407

A

A. the sphenoid bone only.
B. the sphenoid and ethmoid bones.
C. the zygomatic and palatine bones.
D. the sphenoid and maxilla.
E. None of the above

The inferior orbital fissure is formed by the orbital surface of the greater wing of the sphenoid and the orbital surface of the maxilla. The inferior division of the ophthalmic vein passes through the inferior orbital fissure.

Answer 408

A

A. the medial vermal region of the anterior lobe.
B. the lateral region of anterior lobe.
C. the medial vermal region of posterior lobe.
D. the lateral region of posterior lobe.
E. None of the above

Many spinocerebellar fibers are distributed to the medial vermal region of the anterior lobe of the cerebellum.

Answer 409

A

A. Cerebral arteriovenous malformation
B. Metastatic tumor from non–small cell lung carcinoma
C. 1 cm acoustic schwannoma limited to the IAC
D. 1.5 cm petrous apex meningioma not distorting the brainstem
E. 1 cm aneurysm at the top of basilar artery

Aneurysms are not indications for radiosurgery. The prevalence of intracra- nial aneurysm is about 1–5% so observation may be indicated in the majority of healthy patients where small aneurysms are found incidentally.

Answer 410

A

A. Initial symptoms present between ages 20–40 years.
B. It may cause longstanding ventriculitis.
C. It is associated with midline fusion defect.
D. It is characterized by linear growth.
E. Spillage of tumor contents in the subarachnoid space must be avoided.

The lesion is an epidermoid of the cerebellopontine angle. Epidermoid usu- ally presents in the 20- to 40-year age group. Unlike dermoids, they are not associated with midline defect. Spilling of their contents may cause a chem- ical meningitis or ventriculitis; therefore spillage of tumor contents in the subarachnoid space must be avoided. The main goal of therapy is complete excision of the tumor wall and contents to prevent recurrences. Radiation or chemotherapy has no role in the management. Steroids have been shown to be effective in preventing the inflammatory response and possible ventricu- litis associated with these tumors.

Answer 411

A

A. Maple syrup urine disease
B. Adrenoleukodystrophy
C. Wilson’s disease
D. Refsum’s disease
E. Homocystinuria

Adrenoleukodystrophy displays X-linked recessive inheritance. Maple syr- up urine disease is an autosomal recessive metabolic disorder affecting branched-chain amino acids. Adrenoleukodystrophy is a disorder of peroxi- somal fatty acid beta oxidation, which results in accumulation of very-long- chain fatty acids. Wilson’s disease is an autosomal recessive disorder where there is an alteration of the ATP7B gene resulting in inability to excrete cop- per from the body. Refsum’s disease is an autosomal recessive neurological disease that results from overaccumulation of phytanic acid in cells and tis- sues. Homocystinuria is an inherited disorder of the metabolism of the ami- no acid methionine.

Answer 412

A

A. hypervolemic and hypernatremic.
B. hypervolemic and hyponatremic.
C. hypovolemic and hypernatremic.
D. hypovolemic and hyponatremic.
E. None of the above

In cerebral salt wasting syndrome (CSWS), there is inappropriate natriure- sis and diuresis. CSWS is an endocrine condition of low sodium and dehy- dration in response to trauma, intracranial hematoma, or the presence of brain tumors.

Answer 413

A

A. It is the most common cause of intracerebral mass associated with HIV
infection when CD4 counts fall below 100/mm3.
B. Chorea in a patient with AIDS may be pathognomonic of toxoplasmosis.
C. Radiographic images show an asymmetric target sign.
D. The presenting neurological symptom is nonfocal and superimposed on a
global encephalopathy.
E. Therapy includes pyrimethamine and sulfadiazine.

The presenting neurological symptoms and signs in HIV-infected individuals with Toxoplasma encephalitis are focal in nature. Hemiparesis is the most common focal finding.

Answer 414

A

A. frontal bone.
B. sphenoid bone.
C. temporal bone.
D. parietal bone.
E. occipital bone.

The fracture that initiates the leptomeningeal cyst may not be clinically evi- dent but most commonly involves the parietal bone. A growing fracture can occur anywhere, including the skull base. Skull radiographs and CT scans are useful at initial injury and at follow-up.

Answer 415

A

A. Bromocriptine
B. GnRH agonists
C. Octreotide
D. All of the above
E. None of the above

Octreotide is fairly well tolerated; however, gallstone formation can de- velop in 10–20% of patients and is related to the inhibitory effect of oc- treotide on gallbladder motility. Other adverse effects of octreotide are headache, hypothyroidism, cardiac conduction abnormalities, and gastro- intestinal reactions.

Answer 416

A

A. The patient is elderly with a medium-sized tumor.
B. The patient has recently been hospitalized and is on two “heart medications” and a “water pill.”
C. The tumor is on the side of the patient’s only hearing ear.
D. All of the above
E. None of the above

Stereotactic radiosurgery is becoming the standard of care for acoustic neu- romas. The need for a tissue biopsy (which adds additional risk) is becom- ing less important in these tumors because radiological features are usually all that is needed to start treatment. In the event that one is mistaken and a meningioma is truly in the cerebellopontine (CP) angle, the radiosurgical dosage is essentially the same. Tissue diagnoses are especially dangerous in intramedullary spinal cord tumors where the patient is neurologically intact. Empirical radiosurgery performed on spinal cord tumors is being reported to have good results.

Answer 417

A

A. the facial and superior vestibular nerves.
B. the facial and inferior vestibular nerves.
C. the acoustic and superior vestibular nerves.
D. the acoustic and inferior vestibular nerves.
E. None of the above

Bill’s bar is named after William Fouts House (1923–2012), an American otologist referred to as Dr. Bill. This landmark divides the superior compart- ment of the internal acoustic meatus into an anterior and posterior compart- ment. Anterior to Bill’s bar, in the anterior superior quadrant, are the facial nerve and nervus intermedius, and posterior to it in the posterior superior quadrant is the superior division of the vestibular nerve.

Answer 418

A

A. Trigeminal artery
B. Otic artery
C. Hypoglossal artery
D. Proatlantal intersegmental artery
E. Posterior communicating artery

The fetal posterior communicating (Pcom) artery is the most frequent of the persistent fetal circulations. PCom aneurysms are one of the most common aneurysms, accounting for 25% of intracranial aneurysms. These aneurysms are often associated with large or fetal PCom arteries, and the treatment of these aneurysms requires significant diligence in order to maintain flow in the PCom artery.

Answer 419

A

A. Audiogram with pure tones and speech reception
B. Counseling regarding the options of surgery or radiosurgery
C. Workup for a planned craniotomy
D. Consent for angiography and possible embolization
E. Observation

An acoustic neuroma is shown in the radiograph and angiography has no role in the management of acoustic tumor.

Answer 420

A

A. ipsilateral parietal lobe.
B. contralateral parietal lobe.
C. ipsilateral temporal lobe.
D. contralateral temporal lobe.
E. occipital cortex

Interruption of Meyer’s loop fibers in the temporal lobe results in the “pie in the sky” lesion.

Answer 421

A

A. Fragile X syndrome
B. Myotonic dystrophy
C. Olivopontocerebellar atrophy
D. Huntington’s disease
E. Machado–Joseph’s disease

CAG is a common trinucleotide repeat and is translated into a series of unin- terrupted glutamine residues forming a polyglutamine tract.

Answer 422

A

A. chest tightening.
B. lightheadedness.
C. tingling around the mouth.
D. shortness of breath.
E. focal seizures.

Answer 423

A

A. There is progressive attenuation of the cerebellar and premotor areas, but
no change of activity in the primary motor cortex.
B. There is progressive attenuation of the cerebellar, but no change in the
premotor and primary motor cortices.
C. There is no change in the cerebellar, but progressive attenuation of the
premotor and primary motor cortices.
D. There is no change in the cerebellar and premotor cortices, but progressive
attenuation of the primary motor cortex.
E. There is no change in activity of the cerebellar, premotor, or primary motor cortex

If a motor task is performed repeatedly to mastery, there is progressive atten- uation of the cerebellar and premotor areas, with no change of activity of the primary motor cortex. This can be verified with fMRI scanning.

Answer 424

A

A. They can appear crescentic.
B. The lucid interval is seen in ~ 80% of patients.
C. A dry eye postoperatively can occur from traction injury of a nerve.
D. Outcome correlates well with the clinical state prior to surgery.
E. Outcome is inversely correlated with delay in surgery.

The classic lucid interval is seen in only one-third of patients. Traction on the greater superficial petrosal nerve may occur with traction on the floor of the middle fossa, which may result in a dry eye postoperatively. Tacking sutures at surgery may be used for tenting of the dura during healing; however, a small, round JP drain with small holes under bulb suction for a couple days can work just as well, especially in a young patient.

Answer 425

A

A. tumor extension into the middle fossae.
B. a dumbbell shape with constriction in the middle of the tumor.
C. a tumor claimed to be fi brous on previous transsphenoidal resection.
D. All of the above
E. None of the above

All are indications for craniotomy. Pituitary tumors can be effectively debulked with their remnant treated with radiosurgery several months later.

Answer 426

A

A. third ventricle.
B. jugular vein.
C. lateral recess of the fourth ventricle.
D. lumbar cistern.
E. cisterna magna.

An ABI (auditory brainstem implant) is designed to stimulate auditory neu- rons of the cochlear nucleus and is placed in the lateral recess of the fourth ventricle at the time of acoustic tumor removal.

Answer 427

A

A. Root
B. Trunk
C. Division
D. Cord
E. Branch

The dorsal scapular nerve arises from the brachial plexus, usually from the plexus root of C5. This nerve leaves C5 and commonly pierces the middle sca- lene muscle and continues deep to the levator scapulae and the rhomboids.

Answer 428

A

A. Alzheimer’s disease
B. Down’s syndrome
C. Progressive supranuclear palsy
D. SSPE
E. All of the above

All are associated with neurofibrillary tangles. Neurofibrillary tangles are the results of defective assembly of microtubules and/or neurofilaments. These tangles are aggregates of hyperphosphorylated tau proteins.

Answer 429

A

A. The temporal tip
B. The area lateral to cranial nerve I
C. The right-sided inferior frontal gyrus
D. All of the above
E. None of the above

The gyrus rectus may be removed (medial to olfactory nerve) in order to gain better visualization before clipping of an anterior communicating artery aneurysm.

Answer 430

A

A. anterior clinoid process.
B. oculomotor nerve.
C. optic strut.
D. trochlear nerve.
E. vomer.

At the optic strut, the ophthalmic artery pierces the dura to enter the orbit. After the origin of the ophthalmic artery, the ICA passes the tip of the anteri- or clinoid process.

Answer 431

A

A. Sulcus cinguli and parieto-occipital sulcus
B. Calcarine and cingulate
C. Sylvian and calcarine
D. Parieto-occipital and calcarine
E. None of the above

Cuneus is Latin for wedge. The cuneus corresponds to Brodmann area 17 and is a smaller lobe in the occipital lobe of the brain. It is involved in basic visual processing.

Answer 432

A

A. Oxyhemoglobin and bilirubin are the agents likely producing the meningeal response.
B. The size of an intracerebral hematoma is directly related to the chance of
the patient developing vasospasm.
C. Only ~ 1% of cerebral aneurysms result in subdural bleeding.
D. A cerebral aneurysm has a single layer of endothelium.
E. The most important factor in assessing bleeding risk is the temporal relationship to the previous bleed.

The size of the hematoma is inversely related to the chance of the patient developing vasospasm. This reflects the fact that most of the blood has gone into the brain rather than the subarachnoid space.

Answer 433

A

A. reduce cerebral metabolic rate (CMR) and increase cerebral blood flow (CBF).
B. reduce CMR and CBF.
C. increase CMR and CBF.
D. increase CMR and reduce CBF.
E. have no eff ect on CMR and increase CBF.

Volatile anesthetics produce a dose-related reduction in CMR and a simultane- ous increase in CBF. Intravenous anesthetic agents (except ketamine) decrease CMR and CBF in parallel. Volatile anesthetic agents increase CSF production.

Answer 434

A

A. upper trunk.
B. upper and middle trunk.
C. middle trunk.
D. roots of C5 and C6.
E. lower trunk

Note that the median sensory response, mediated by upper trunk fibers, would remain normal in lower trunk plexopathy. Trauma accounts for the majority of brachial plexus plexopathies. A lesion of the brachial plexus can result in motor, sensory, and sympathetic findings.

Answer 435

A

A. Horner’s syndrome.
B. Frey’s syndrome.
C. Chagas’s disease.
D. Familial dysautonomia.
E. Huntington’s disease

An abnormal skin histamine response is a characteristic feature of patients with familial dysautonomia. Familial dysautonomia is also called Riley–Day syndrome and hereditary sensory and autonomic neuropathy type III. Famil- ial dysautonomia is seen almost exclusively in Ashkenazi Jews and is inherit- ed in an autosomal recessive fashion.

Answer 436

A

A. Foramen ovale
B. Foramen magnum
C. Jugular foramen
D. All of the above
E. None of the above

The jugular foramen transmits a number of vital structures from the posteri- or fossa to the neck. This foramen is situated at the junction of the temporal and occipital bone. It is the site for glomus jugulare tumors, schwannomas, and meningiomas. Glomus tumors produce local bony destruction, whereas schwannomas produce a smooth-edged enlargement of the foramen.

Answer 437

A

A. Diagonal band of Broca
B. Fasciculus retroflexus
C. Ansa lenticularis
D. Lenticular fasciculus
E. Obex

Acetylcholine and substance P are transmitters in this projection. The fas- ciculus retroflexus is also known as the habenulointerpeduncular tract. The habenula receives input from the brain via the stria medullaris thalami and outputs to many midbrain areas involved in releasing neurotransmitters such as dopamine, norepinephrine, and serotonin.

Answer 438

A

A. They form as part of normal aging but are not aff ected by hypertension.
B. They form as part of normal aging and are accentuated by hypertension.
C. They are not part of the normal aging process and are not aff ected by
hypertension.
D. They are not part of normal aging and are accentuated by hypertension.
E. They usually aff ect blood vessels > 300 μm in diameter.

Charcot–Bouchard aneurysms (also known as military aneurysms or microa- neurysms) are aneurysms of the brain vasculature that occur in small blood vessels < 300 μm diameter. They are most often located in the lenticulostriate vessels of the basal ganglia and are associated with chronic hypertension.

Answer 439

A

A. dizziness, ataxia, and balance problems.
B. expressive aphasia with positive Rhomberg’s sign.
C. tinnitus and reduced hearing in the right ear with frequent falling.
D. ptosis of the right eye with weakness of external ocular muscles.
E. weakness in the right side of body, especially in the upper limbs

The lesion is a cavernous sinus meningioma. Lesions in this region that are approximately ≤ 3 cm are ideal for radiosurgery.

Answer 440

A

A. Superior cerebellar artery
B. Basilar artery
C. AICA
D. PICA
E. Vertebral artery

The anterior inferior cerebellar artery loops around cranial nerves VII and VIII.

Answer 441

A

A. Olive
B. Tuberculum cinereum
C. Vagal trigone
D. Facial colliculus
E. Origin of the glossopharyngeal nerve

The facial colliculus is located in the pontine half of the rhomboid fossa. The tuberculum cinereum (not to be confused with the tuber cinereum of the hypothalamus) is a surface eminence of the medulla that overlies the spinal trigeminal tract and nucleus.

Answer 442

A

A. Arteriovenous malformations can contain neural parenchyma.
B. Calcifi cation is common in cavernous malformations.
C. Hemosiderin-laden macrophages are common in venous malformations.
D. Capillary malformations do not show progressive growth.
E. Early angiographic fi lling is seen with AVMs

Hemosiderin-laden macrophages are seen with cavernous malformation.

Answer 443

A

A. clear beneficialeff ect, improve angiographic vasospasm, and increase CBF.
B. clear beneficialeff ect and improve angiographic vasospasm and functional
outcome.
C. modest beneficial effect.
D. detrimental effect.
E. detrimental effect and decrease CBF

Calcium channel–blocking agents can be expected to have a beneficial effect in the patient; however, there is no lasting effect on angiographic vasospasm and no increase in CBF. The evidence for calcium channel blocking agents is not beyond all doubt, but given the potential benefits and modest risks of this treatment, it is indicated in patients with aneurysmal SAH.

Answer 444

A

A. the plexal point, tonsillomedullary segment.
B. the choroidal point, tonsillomedullary segment.
C. the plexal point, telovelotonsillar segment.
D. the choroidal point, telovelotonsillar segment.
E. None of the above

The top of the cranial loop is the choroidal point, located in the teloveloton- sillar segment of the PICA. The plexal point is the point where the anterior choroidal artery enters the choroidal fissure.

Answer 445

A

A. the anterior right hemisphere.
B. the posterior right hemisphere.
C. the anterior left hemisphere.
D. the posterior left hemisphere.
E. None of the above

The principal anatomical substrate of perceptual organization is the posteri- or right hemisphere. Posterior right hemisphere lesions tend to produce the most severe deficits of constructional praxis.

Answer 446

A

A. Trautmann’s triangle.
B. Parkinson’s triangle.
C. Wernicke’s triangle.
D. Labbé’s triangle.
E. Calot’s triangle.

Trautman’s triangle is a space bounded by bony labyrinth anteriorly, sigmoid sinus posteriorly, and dura containing superior petrosal sinus superiorly. This area is a route where infections of temporal bone may traverse and af- fect the cerebellum.

Answer 447

A

A. the trapezoid body.
B. the commissure of Probst.
C. the juxtarestiform body.
D. All of the above
E. None of the above

The lateral lemniscus is a tract of axons in the brainstem that carries infor- mation about sound from the cochlear nucleus to various brainstem nuclei and ultimately the contralateral inferior colliculus of the midbrain.

Answer 448

A

A. choroid plexus tumor.
B. colloid cyst.
C. central neurocytoma.
D. chordoid glioma.
E. glioblastoma multiforme.

These tumors are rare, but they must enter into the differential diagnosis of a solid third ventricle enhancing mass that is glial fibrillary acidic protein (GFAP) positive.

Answer 449

A

A. Three tumors, each measuring 1–1.5 cm within the right hemisphere
B. A solitary left parietal tumor measuring 2cm × 2cm × 1.8cm
C. A 2.5 cm left mesial temporal tumor with clinical signs of herniation
D. Tumors in both the supratentorial and the infratentorial compartment
E. No tissue biopsy from the brain

Impending herniation regardless of the tumor size or number is an indica- tion for open surgery. One can proceed empirically with cranial radiosurgery without tissue biopsy with good results. A short course of steroids after ra- diosurgery is indicated for swelling prophylaxis.

Answer 450

A

A. outer aspect of the lesser wing of the sphenoid.
B. inner aspect of the lesser wing of the sphenoid.
C. outer aspect of the greater wing of the sphenoid.
D. inner aspect of the greater wing of the sphenoid.
E. cavernous sinus.

The sphenoparietal sinus runs along the ridge of the sphenoid lesser wing and collects tributaries of the sylvian veins to empty into the cavernous sinus.

Answer 451

A

A. on the lateral aspect of the frontal lobe.
B. on the medial aspect of the frontal lobe.
C. on the lateral aspect of the occipital lobe.
D. on the medial aspect of the occipital lobe.
E. on the medial aspect of the parietal lobe

The precuneus is bounded posteriorly by the parieto-occipital sulcus. This area is involved with self-consciousness, memory, and visual-spatial processing.

Answer 452

A

A. capillary telangiectasia.
B. venous malformation.
C. arteriovenous malformation.
D. cavernous malformation.
E. dural arteriovenous fi stula

Venous malformations may occur in up to 2% of individuals. Venous vascular malformations are also known as venous angiomas. A newer term, develop- mental venous anomalies (DVA), has been recommended as a more appropri- ate term.

Answer 453

A

A. ophthalmic artery.
B. maxillary artery.
C. middle meningeal artery.
D. occipital artery.
E. facial artery.

The anterior meningeal artery is also known as the anterior falx artery. This artery can be enlarged in frontal tumors, falcine meningiomas, and moyamoya disease.

Answer 454

A

A. the middle cerebral artery.
B. the internal cerebral artery.
C. the recurrent artery of Heubner.
D. the posterior communicating artery.
E. None of the above

The recurrent artery of Heubner enters the anterior perforating substance and supplies the head of the caudate, anterior limb of the internal capsule, the anterior putamen and GP, the septal nuclei, and the inferior frontal lobe. Otto Heubner was a German pediatrician who made contributions in cere- brospinal meningitis, syphilitic endarteritis obliterans, aseptic practices in the hospital environment, and infectious disease.

Answer 455

A

A. type I, longitudinal
B. type II, longitudinal
C. type I, circular
D. type II, circular
E. None of the above

The external sphincter is composed of circularly arranged striated muscle fibers that are mostly type I (slow twitch).

Answer 456

A

A. It should be suspected in a multitrauma victim with mandibular fractures
and submental lacerations.
B. Prevertebral soft tissue swelling may be the only clue to its diagnosis.
C. The gap between the occipital condyles and condylar surface of the atlas is >5 mm.
D. The distance between the tip of the dens and the basion is > 12mm
E. The clivus line is not tangential to the odontoid.

Harris’s method is the most clinically useful means of assessing atlanto-oc- cipital dislocation. The basion should lie within 12 mm of the superior con- tinuation of a line drawn along the posterior cortex of the body of the axis, and the distance of the basion and tip of the odontoid is normally < 12 mm.

Answer 457

A

A. dendrite.
B. soma.
C. hillock.
D. node of Ranvier.
E. axon terminal.

There are many more sodium channels located at the axon hillock. Synaptic inputs are summated in the region of the action hillock and the action poten- tial is initiated here.

Answer 458

A

A. Pilocytic astrocytom
B. Ganglioglioma
C. DNET
D. Astrocytoma
E. Pleomorphic xanthoastrocytom

Ganglioglioma is twice as common as dysembryoplastic neuroepithelial tu- mors (DNET) in causing temporal lobe epilepsy. Gangliogliomas occur mostly in children and young adults, and calcification is frequently present on imag- ing studies of these tumors.

Answer 459

A

A. Trigeminal neuralgia refractory to medication
B. Glossopharyngeal neuralgia in a patient with carbamazepine
hypersensitivity
C. Unilateral essential tremors refractory to medication
D. Parkinson’s tremor in the left upper extremity with levodopa-induced
dyskinesias
E. Huntington’s chorea

Huntington’s chorea is not an indication for radiosurgery.

Answer 460

A

A. The entire insula drains to the deep venous system.
B. The entire insula drains to the superfi cial venous system.
C. The anterior portion of the insula drains to the deep system.
D. The posterior portion of the insula drains to the superfi cial system.
E. None of the above

There is a tendency for the posterior insula to drain more frequently into the deep system, whereas the anterior portion of the insula drains to the super- ficial venous system.

Answer 461

A

A. Posterolateral fi ssure
B. Horizontal fi ssure
C. Dorsolateral fi ssure
D. Primary fi ssure
E. Postlunate fi ssure

The primary fissure separates the anterior cerebellar lobe from the posterior cerebellar lobe. The horizontal fissure is located within the posterior lobe. The dorsolateral fissure is synonymous with the posterolateral fissure and separates the flocculonodular lobe from the posterior lobe.

Answer 462

A

A. Dural arteriovenous fi stulas are believed to be acquired.
B. Normal neural parenchyma is seen within juvenile AVMs.
C. Glomus AVMs may have associated aneurysms.
D. Acute progression is most likely due to venous congestion.
E. Dural AV fi stulas have a female predilection

Dural arteriovenous (AV) fistulas have a male predominance, are acquired lesions, have low flow, rarely hemorrhage, and have a gradual onset of symptoms.

Answer 463

A

A. 1–8 mL/100 g/min.
B. 8–23 mL/100 g/min.
C. 23–30 mL/100 g/min.
D. 30–40 mL/100 g/min.
E. 40–50 mL/100 g/min

Neurons in the penumbra (8–23 mL/100 g/min) survive but do not function. Below 8 mL/100 g/min neurons cannot recover. Hypothermia can allow a modestly prolonged survival at these blood flows.

Answer 464

A

A. Substantia nigra
B. Pedunculopontine nucleus
C. Zona incerta
D. Subthalamic nucleus
E. None of the above

The zona incerta is the gray matter between the thalamic and lenticular fas- ciculi. Laterally, the zona incerta is continuous with the thalamic reticular nucleus.

Answer 465

A

A. Medial parts of the frontal lobes
B. Preoptic region of the hypothalamus
C. Basal ganglia
D. All of the above
E. None of the above

Evidence for these areas influencing micturition comes from positron emis- sion tomographic scanning.

Answer 466

A

A. Lateral, inferior
B. Lateral, superior
C. Medial, inferior
D. Medial, superior
E. None of the above

The juxtarestiform body carries both afferent and efferent fibers connecting the vestibular nuclei and the flocculonodular lobe and fastigial nucleus of the cerebellum. It coordinates balance and eye movements by communication between the vestibular apparatus and the cerebellum.

Answer 467

A

A. IA
B. IB
C. II
D. III
E. IV

Type II fibers connect to nuclear chain fibers and static nuclear bag fibers. These connections are flower-spray endings and insert into the ends of the fiber.

Answer 468

A

A. Ventral spinocerebellar tract
B. Dorsal spinocerebellar tract
C. Gracile fasciculus
D. Cuneate fasciculus
E. None of the above

In a caudalis dorsal root entry zone (DREZ) operation, the electrode pene- trates the dorsal spinocerebellar tract into the trigeminal tract and deeper caudalis nucleus.

Answer 469

A

A. has no corresponding area in the intracranial pressure (ICP) waveform.
B. corresponds to the area between P1 and P2 of the ICP waveform.
C. corresponds to the area between P2 and P3 of the ICP waveform.
D. corresponds to the area after P3 of the ICP waveform.
E. None of the above

The arterial dicrotic notch corresponds to the area between the tidal (P2) and dicrotic (P3) peaks of the ICP waveform.

Answer 470

A

A. Anterior perforated substance
B. Posterior perforated substance
C. Tuber cinereum
D. Medial geniculate body
E. Lateral geniculate body

The basal vein of Rosenthal receives tributaries from the medial temporal lobe and brainstem. It begins at the anterior perforated substance.

Answer 471

A

A. frontal horn.
B. third ventricle.
C. trigone of lateral third ventricle.
D. occipital horn.
E. foramen of Monro

The trigone of the lateral ventricle is a triangular area defined by the tempo- ral horn inferiorly, the occipital horn posteriorly, and the body of the lateral ventricle anteriorly.

Answer 472

A

A. Cerebellum
B. Rostral midbrain
C. Rostral pons
D. Caudal midbrain
E. Caudal pons

Decussation of the superior cerebellar peduncles occurs in the caudal mid- brain tegmentum at the level of the inferior colliculus. The superior cere- bellar peduncle is one of the structures that connects the cerebellum to the midbrain. The ventral spinocerebellar tract enters the cerebellum through the superior cerebellar peduncle.

Answer 473

A

A. superior thyroid artery.
B. ascending pharyngeal artery.
C. lingual artery.
D. facial artery.
E. occipital artery.

The ascending pharyngeal artery supplies these nerves before anastomosing with vertebral artery branches. This artery also supplies the pharynx.

Answer 474

A

A. ipsilateral lateral and medial rectus palsies.
B. ipsilateral lateral and contralateral medial rectus palsies.
C. contralateral lateral and ipsilateral medial rectus palsies.
D. contralateral lateral and medial rectus palsies.
E. None of the above

Destruction of the abducens nucleus (subcortical center for lateral gaze) re- sults in an ipsilateral lateral rectus and contralateral medial rectus palsy on attempted lateral gaze.

Answer 475

A

A. the medial lemniscus.
B. the lateral lemniscus.
C. the corticospinal tracts.
D. All of the above
E. None of the above

Brainstem auditory evoked responses test the ear and the brain. They meas- ure the timing of electrical waves from the brainstem in response to clicks in the ear. Waveforms represent specific anatomical points along the auditory pathway.

Answer 476

A

A. the inferior rectus.
B. the inferior oblique.
C. the medial rectus.
D. All of the above
E. None of the above

The lateral subnucleus of CN III innervates the inferior rectus, inferior oblique, and medial rectus. The medial subnucleus innervates the contralat- eral superior rectus. The central subnucleus innervates the levator palpebrae superioris.

Answer 477

A

A. Brodmann area 3a.
B. Brodmann area 3b.
C. Brodmann area 2.
D. Brodmann area 1.
E. None of the above

The primary sensory cortex is Brodmann areas 3, 1, and 2. This area of the cortex is organized somatotopically, having the pattern of a homunculus

Answer 478

A

A. Symmetric involvement
B. Pain
C. Saddle anesthesia
D. Bladder and bowel symptoms
E. Sudden onset

Pain is more common in cauda equina lesions than in conus lesions. Motor loss is more marked in cauda lesions, and bladder and rectum are involved later in cauda lesions. The onset of cauda lesions is more gradual than that of conus lesions. Also cauda lesions are more commonly unilateral than co- nus lesions. Cauda equina lesions can occur with compression in the lower lumbar region, they are a medical emergency, and patients should be admit- ted with urgent surgery to decompress the nerves and stabilize the spine if necessary. Approximately 1% of a busy spine practice can be cauda equina conditions, yet insurance companies and some hospitals will incorrectly and unethically insist that such surgeries can be performed electively at a later time for cost savings.

Answer 479

A

A. III.
B. IV.
C. V.
D. VI.
E. VII.

MPNSTs are also known as schwannomas, neurofibrosarcomas, and neuro- sarcomas. The trigeminal nerve is most commonly involved only because it is the largest cranial nerve.

Answer 480

A

A. IV (trochlear) and V (trigeminal)
B. III (oculomotor) and IV
C. III and II (optic)
D. V and VI (abducens)
E. II and IV

The superior ophthalmic vein courses into the anterior cavernous sinus above the sixth nerve and below the first division of the trigeminal nerve. The superior ophthalmic vein is exterior to the annulus of Zinn.

Answer 481

A

A. the medial wall of the frontal horn.
B. the fl oor of the temporal horn.
C. the lateral wall of the occipital horn.
D. the roof of the lateral ventricle.
E. None of the above.

The caudate nucleus forms the lateral wall of the frontal horn, body, and trigone of the lateral ventricle. It forms the roof of the temporal horn. The caudate does not extend to the occipital horn. The caudate nucleus makes up the basal ganglia along with the putamen and globus pallidus.

Answer 482

A

A. It arises from the principal sensory nucleus of V.
B. It terminates on the VPM thalamus.
C. It conveys touch and pressure information from the face.
D. It is an uncrossed tract.
E. All of the above

The dorsal trigeminothalamic tract is the rostral equivalent of the dorsal-col- umn medial-lemniscal system.

Answer 483

A

A. Skin
B. Subcutaneous tissue
C. Galea
D. Loose areolar tissue
E. Periosteum

The loose areolar tissue contains the valveless emissary veins. Emissary veins connect the extracranial venous system with the intracranial venous sinuses.

Answer 484

A

A. Adrenergic fi bers
B. Cholinergic fi bers
C. Nitric Oxide
D. VIP
E. None of the above

Apocrine sweat glands of the axilla are innervated by adrenergic fibers and secrete in response to mental stress. The eccrine sweat glands have choliner- gic innervation.

Answer 485

A

A. Just after birth
B. Childhood
C. Adolescence
D. Young adulthood
E. Late adulthood

The water content of the nucleus pulposus is maximum at birth and declines throughout life, the greatest decline occurring during the growth phase in childhood.

Answer 486

A

A. the claustrum.
B. the globus pallidus.
C. the corpus callosum.
D. the thalamus.
E. None of the above

The tapetum are corpus callosum fibers connecting the temporal and occip- ital lobes.

Answer 487

A

A. dominant frontal lobe.
B. nondominant frontal lobe.
C. dominant parietal lobe.
D. nondominant parietal lobe.
E. occipital lobe.

Apraxia is a disorder of motor planning. Dressing apraxia can be tested by having the patient put on a jacket with the sleeves first deliberately turned inside-out.

Answer 488

A

A. valveless arachnoid villi.
B. pressure-insensitive valves of the arachnoid villi.
C. pressure-sensitive one-way valves of the arachnoid villi.
D. pressure-insensitive valveless arachnoid villi.
E. cranial nerves

Cerebrospinal fluid is reabsorbed into the bloodstream through pressure-sen- sitive one-way valves in the arachnoid villi.

Answer 489

A

A. CLIP.
B. beta-lipotropin.
C. alpha-MSH.
D. POMC.
E. p53.

Proopiomelanocortin (POMC) gives rise to adrenocorticotropic hormone (ACTH) and beta-lipotropin. ACTH gives rise to alpha-MSH and CLIP. Beta-li- potropin gives rise to beta-endorphin and gamma-lipotropin.

Answer 490

A

A. It involves autoantibodies directed against acetylcholine receptors at the
neuromuscular junction,
B. The prevalence is between 1 in 10,000 to 15,000.
C. Juvenile MG is more common in Asians.
D. There is an increased incidence of an underlying thymoma in late onset MG.
E. Late-onset MG is more common in females.

Late-onset myasthenia gravis (onset after age 50) is more common in males. Early-onset myasthenia gravis (onset from ages 18 to 50) is more common in females.

Answer 491

A

A. sphenoid bone.
B. occipital bone.
C. sphenoid and temporal bones.
D. temporal bone.
E. temporal and occipital bones.

The ICA enters the cranium via the carotid canal of the temporal bone.

Answer 492

A

A. It has a nucleus located in the midbrain tegmentum at the level of the
inferior colliculus.
B. It decussates in the superior medullary velum.
C. It exits the brainstem from the dorsal surface of the brainstem.
D. It courses lateral to the frenulum of the superior medullary velum.
E. Damage to the nucleus results in dysfunction of the superior oblique muscle on that side.

Damage to the trochlear nucleus results in damage to the contralateral superior oblique because the fibers decussate in the superior medullary velum.

Answer 493

A

A. the lambdoid, occipitomastoid, and parietomastoid sutures.
B. the lambdoid, sagittal, and occipitomastoid sutures.
C. the lambdoid, sagittal and parietomastoid sutures.
D. the sagittal and occipitomastoid sutures.
E. None of the above

The asterion is located at the intersection of the lambdoid, occipitomastoid, and parietomastoid sutures. This point reliably marks the anteroposterior level of the transverse-sigmoid sinus junction.

Answer 494

A

A. Posterior nucleus
B. Ventromedial nucleus
C. Lateral nucleus
D. Anterior nucleus
E. None of the above

The anterior nucleus of the hypothalamus is involved in thermal regulation (dissipation of heat). The anterior nucleus stimulates the parasympathetic nervous system. Destruction of this nucleus results in hyperthermia.

Answer 495

A

A. Occipitoatlantal joint
B. Atlantoaxial joint
C. Sacrum
D. All of the above
E. None of the above

Disks make up roughly 25% of the spine’s height. There is no disk at the occip- itoatlantal joint, atlantoaxial joint, sacrum, or coccyx. Traction and inversion table therapy can help to slow down the desiccation and shortening of disk space height.

Answer 496

A

A. Serum sodium < 135 mEq/L
B. Serum osmolarity < 280 mOsm/L
C. Hypervolemia
D. Urine sodium > 20 mmol/24 h
E. Urine osmolarity > serum osmolarity

SIADH is a type of hyponatremia characterized by euvolemia.

Answer 497

A

A. Gunn’s syndrome
B. Joubert’s syndrome
C. De Morsier’s syndrome
D. Duane’s syndrome
E. None of the above

Duane’s syndrome produces a characteristic pattern of eye movement with failure of abduction and retraction of the globe on adduction; the third nerve innervates the lateral rectus due to developmental failure of motor neurons in the sixth nerve nucleus. Alexander Duane was an American ophthalmolo- gist who published “A New Classification of the Motor Anomalies of the Eye” in 1897.

Answer 498

A

A. Cimetidine
B. Coumadin
C. Carbamazepine
D. Isoniazid
E. Sulfa drugs

Dilantin levels are decreased by carbamazepine.

Answer 499

A

A. Olivocerebellar
B. Reticulocerebellar
C. Pontocerebellar
D. All of the above
E. None of the above

Olivocerebellar fibers end as climbing fibers, and aspartate is a common neu- rotransmitter in this connection. Reticulocerebellar and pontocerebellar fib- ers end as mossy fibers.

Answer 500

A

A. tumor location.
B. tumor size.
C. time to surgery.
D. chemotherapy and radiation.
E. None of the above

Paraganglioma is a rare neuroendocrine neoplasm the great majority of which are benign. About 3% of these tumors are malignant and are able to produce distant metastases. Tumor location is often more relevant than histology and other factors in assessing the prognosis of paraganglioma pa- tients. For example, the metastatic rate of para-aortic paraganglioma is high (~ 30%), whereas that of carotid body tumors is much lower (~ 6%). Most paragangliomas are either asymptomatic or present as a painless mass.

Answer 501

A

A. IV and V1.
B. V1 and V2.
C. V2 and V3.
D. V3 and VI.
E. None of the above

The anteromedial triangle of the middle fossa can be used to expose portions of the cavernous sinus and lateral sphenoid wing.

Answer 502

A

A. Subcortical white matter of the occipital lobes bilaterally with little to no edema
B. Subcortical white matter of the occipital lobes bilaterally with edema
C. The cortical ribbon of the parietal lobes bilaterally
D. The cortical ribbon and subcortical white matter bilaterally
E. The cortical ribbon with sparing of the subcortical U-fibers

Hyperperfusion encephalopathy is believed to result from the failure of intrac- ranial vessels to compensate adequately for rapid increases of blood pressure. The posterior brain regions exhibit reversible edema bilaterally. This condi- tion is also known as PRES (posterior reversible encephalopathy syndrome). Patients can present with headaches, seizures, and/or visual disturbances.

Answer 503

A

A. Foramen ovale and spinosum
B. Foramen ovale and rotundum
C. Foramen rotundum and spinosum
D. Foramen spinosum and lacerum
E. Foramen lacerum and ovale

Glasscock’s triangle is also known as the posterolateral triangle. Its contents are the foramen spinosum, horizontal petrous ICA, and infratemporal fossa.

Answer 504

A

A. The vast majority of patients recover completely.
B. The edema tends to resorb completely.
C. The vertebrobasilar system is vulnerable due to extensive sympathetic
innervation.
D. A similar condition may occur after a carotid endarterectomy.
E. Patients with hyperperfusion encephalopathies often have labile
blood pressures.

The posterior circulation has sparse sympathetic innervation and is less well protected from hyperperfusion encephalopathies.

Answer 505

A

A. It separates the frontal lobe from the parietal lobe.
B. It separates the motor cortex from the sensory cortex.
C. It extends into the paracentral lobule.
D. It is usually continuous with the lateral sulcus.
E. It is located on the lateral convex surface of the hemisphere.

The central sulcus rarely joins the lateral sulcus. The central sulcus separates the parietal lobe from the frontal lobe and the primary motor cortex from the primary sensory cortex. This was originally called the fissure of Rolando after Luigi Rolando, an Italian anatomist who published extensively on brain anatomy and function in the 1800s.

Answer 506

A

A. Normal intraocular pressure
B. Ipsilateral flushing
C. Decreased local skin temperature
D. Female predominance
E. No aura is seen with common migraines

Ipsilateral flushing is seen with cluster headaches. Cluster headaches also have an increased intraocular pressure, increased local skin temperature, and male predominance, and are seen in older patients. Migraine headaches can be improved with Botox (Allergan) injections to the scalp musculature. Many patients given the diagnosis of migraine headaches may have cervicogenic headaches, and a cervical MRI is helpful in determining this. Cervicogenic headaches have a characteristic triad of headache, pressure behind the eye, and a swooshing sound (or tinnitus) in the ear.

Answer 507

A

A. Anton’s syndrome.
B. Adie’s syndrome.
C. Cogan’s syndrome.
D. Vernet’s syndrome.
E. Balint’s syndrome.

The syndrome described is Balint’s syndrome. It is of interest to note that functional “streams” of visual processing have been postulated. The “where” stream is destined for further processing in the parietal lobes and subserves spatial localization and the control of eye movements. The “what” stream is destined for the temporal lobes and is concerned with the identification of objects and color vision. Evidence for this came from studying patients with Balint’s syndrome.

Answer 508

A

A. the basal ganglia.
B. the anterior commissure.
C. the caudate nucleus.
D. All of the above
E. None of the above

The amygdala is not removed completely in this procedure. The most medial part abuts the basal ganglia, anterior commissure, and tail of the caudate.

Answer 509

A

A. Lateral, parallel
B. Medial, parallel
C. Lateral, perpendicular
D. Medial, perpendicular
E. None of the above

The anterior choroidal artery can be divided into two segments: the cisternal segment extends from its origin until the choroidal fissure and the intraven- tricular segment after entering the choroidal fissure.

Answer 510

A

A. Piriformis
B. Obturator internus
C. Quadratus femoris
D. Gluteus minimus
E. Gluteus maximus

The gluteus minimus is a medial rotator of the thigh. The others listed are all lateral rotators. The gluteus minimus is the smallest of the three gluteal muscles. Paralysis of this muscle may be caused by a superior gluteal nerve palsy.

Answer 511

A

A. Parkinson’s disease
B. Shy–Drager’s syndrome
C. Multiple system atrophy
D. Diffuse Lewy body dementia
E. Paralysis agitans

Lewy bodies are concentrically laminated, round bodies found in vacuoles in the cytoplasm. They are absent in multiple system atrophy (MSA). Lewy bodies were discovered by Frederic Lewy, an American neurologist.

Answer 512

A

A. septal vein.
B. thalamostriate vein.
C. caudate vein.
D. basal vein of Rosenthal.
E. vein of Galen.

The thalamostriate vein lies in the groove between the thalamus and caudate nucleus and receives blood from both.

Answer 513

A

A. anterior to the target.
B. posterior to the target.
C. medial to the target.
D. lateral to the target.
E. close to the target.

Paresthesias of the fingertips or mouth indicate that the electrode is too pos- terior (in the region of the ventralis caudalis [VC]). The electrode needs to be repositioned more anteriorly. High-frequency stimulation of the VC causes contralateral paresthesias. The threshold for inducing contralateral paresthe- sias is higher in the ventralis intermedius (Vim) (target), and it is usually > 3 V.

Answer 514

A

A. Streptococcus pneumoniae.
B. Haemophilus influenzae.
C. Neisseria meningitidis.
D. Proteus.
E. None of the above

Deficiency of the late complement components predisposes to Neisseria meningitidis. Deficiency of early complement components tend to be linked with autoimmune diseases. Complement deficiencies are said to comprise between 1 and 10% of all primary immunodeficiencies.

Answer 515

A

A. body.
B. trigone.
C. temporal horn.
D. occipital horn.
E. frontal horn.

Meningiomas and choroid plexus papillomas are the most common neo- plasms of the trigone of the lateral ventricle. Meningiomas originate from the arachnoid cap cells of the choroid plexus and the tela choroidea. Intraven- tricular meningiomas present in mid adulthood with a female predilection.

Answer 516

A

A. the size of the largest metastasis.
B. the extent of systemic disease.
C. the number of visible metastases on MRI scan.
D. the neurological condition preoperatively.
E. proximity to the eloquent cortex.

The status of systemic disease is the most important determinant for survival.

Answer 517

A

A. Ia (A-).
B. Ib (A-).
C. II (A-).
D. III (A-).
E. IV (C).

Golgi tendon organs are associated with Ib (A-a) fibers. Muscle spindles are associated with Ia (A-a) fibers. Slow pain and temperature are carried by un- myelinated fibers IV (C).

Answer 518

A

A. caused by staphylococci; occur in the cervical cord.
B. caused by streptococci; occur in the cervical cord.
C. caused by staphylococci; occur in the thoracic cord.
D. caused by streptococci; occur in the thoracic cord.
E. caused by staphylococci; occur in the lumbar cord.

Staphylococcus aureus causes ~ 60–90% of cases of spinal epidural abscesses. The most frequent location is the thoracic epidural space.

Answer 519

A

A. Staphylococcus is the organism implicated in a majority of cases.
B. Symptoms include shunt failure, headache, nausea, and vomiting.
C. Elevated temperature is a more reliable sign of infection in VA as opposed to VP shunts.
D. There is a greater risk of shunt infection with distal revision than with proximal revision.
E. Staphylococcus infections may cause obstruction without fever.

There is a greater risk of shunt infection with proximal revisions.

Answer 520

A

A. Liposarcoma
B. Fibrosarcoma
C. Angiosarcoma
D. Chondrosarcoma
E. Osteosarcoma

The development of sarcomas after cranial irradiation is well described. Fi- brosarcomas are the most common type arising in the sella after irradiation for pituitary tumors.

Answer 521

A

A. disinhibition of the subthalamic nucleus.
B. high activity of Gpi/SNr.
C. inhibition of the motor thalamus.
D. All of the above
E. None of the above

Dopamine plays a central role in Parkinson’s disease, attention deficit hyper- activity disorder, schizophrenia, and drug addiction.

Answer 522

A

A. It is due to disruption of the pituitary stalk.
B. There is degeneration of distal axons in the region of dissection.
C. Stored ADH is depleted.
D. All of the above
E. None of the above

The sequence of antidiuretic hormone (ADH) release after surgery is tripha- sic. Initially, excessive diuresis is due to disruption of the pituitary stalk. Then there is a release of ADH in large amounts from degeneration of distal axons. Finally the stored ADH disappears, and excessive diuresis returns

Answer 523

A

A. Strongyloides
B. Schistosomiasis
C. Paragonimiasis
D. Neurocysticercosis
E. Echinococcus

Patients with infection commonly present with cord compression due to the predilection of echinococcus for bone, particularly vertebrae. With- in bone tissue hyatid cysts enlarge by daughter cyst formation. The goal of surgery is removal of the cysts; an anterior or circumferential approach is recommended.

Answer 524

A

A. cingulated gyrus.
B. prefrontal cortex.
C. substantia nigra.
D. lateral lemniscus.
E. inferior parietal lobule.

The mediodorsal nucleus is reciprocally connected to the prefrontal cortex. The prefrontal cortex is the cerebral cortex, which covers the front part of the frontal lobe. It contains Brodmann areas 9, 10, 11, 12, 46, and 47.

Answer 525

A

A. subependyma.
B. gray–white junction.
C. meninges.
D. frontal lobe.
E. corpus callosum.

Lymphoma metastatic to the brain tends to localize to the meninges, as op- posed to the intraparenchymal (often subependymal) location of primary tumors.

Answer 526

A

A. Anterior commissure
B. Posterior commissure
C. Hippocampal commissure
D. All of the above
E. None of the above

The hippocampal commissure is located in the posterior component of the forniceal structure.

Answer 527

A

A. It is the largest of the intralaminar nuclei.
B. It receives input from the globus pallidus.
C. It projects to the striatum.
D. It projects diffusely to the entire neocortex.
E. It is reciprocally connected to areas 41 and 42.

The centromedian nucleus is reciprocally connected to the motor cortex (area 4).

Answer 528

A

A. Medial, anterior
B. Medial, posterior
C. Lateral, anterior
D. Lateral, posterior
E. None of the above

During surgery around the mastoid process, care must be taken to avoid inju- ry to cranial nerve VII as it exits through the stylomastoid foramen, which is located medial to the insertion of the posterior belly of the digastric muscle at the digrastric groove.

Answer 529

A

A. division of the anterior corpus callosum.
B. retraction on the fornix.
C. circulatory disturbance in the SMA.
D. All of the above
E. None of the above

In addition, postoperative amnesia may result from manipulation of the fornix.

Answer 530

A

A. Dentate nucleus
B. Globose nucleus
C. Emboliform nucleus
D. All of the above
E. None of the above

The rostral one-third of the red nucleus receives dentate fibers, and the cau- dal two-thirds receive fibers from the interposed nuclei. Stimulation of the red nucleus elicits increased tone in the contralateral flexors. The red nucleus gets its pale pink color from hemoglobin and ferritin, which are present in the red nucleus.

Answer 531

A

A. Phentolamine
B. Atropine
C. Phenylephrine
D. Amphetamine
E. Phenoxybenzamine

Phenoxybenzamine is a nonselective, irreversible alpha blocker used in the treatment of hypertension, especially hypertension caused by pheochromo- cytoma. It is also used in complex regional pain syndrome type 1 due to its antiadrenergic effects.

Answer 532

A

A. Forty percent of the energy consumed is for maintenance of ionic gradients.
B. Once EEG silence is induced, barbiturates will not produce further reductions in (CMRO2).
C. Once EEG silence is induced, temperature reduction does produce further reductions in (CMRO2).
D. The normal rate is ~5 mL/100 g brain/min.
E. Ketamine anesthesia decreases CMRO2.

Ketamine anesthesia increases CMRO2. All other anesthetic drugs decrease CMRO2. The main energy demands of the brain are those of ion flux related to excitation and conduction. Continuous cerebral circulation is absolutely required to provide sufficient oxygen.

Answer 533

A

A. Centromedian
B. Ventral anterior
C. Ventral lateral
D. All of the above
E. None of the above

The globus pallidus projects to three thalamic nuclei via the thalamic fascic- ulus (FFH1).

Answer 534

A

A. posterior cerebral artery.
B. posterior choroidal artery.
C. middle cerebral artery.
D. anterior choroidal artery.
E. occipital artery.

The major blood supply to ventricular trigone meningiomas is constant, aris- ing from the anterior choroidal artery, with only a minor component arising from the posterior choroidal artery.

Answer 535

A

A. -fetoprotein
B. -HCG
C. CBC, PT, PTT
D. All of the above
E. None of the above

Elevated markers are indicative of malignant germ cell tumors, and these tumors can be radiosensitive and chemosensitive, precluding surgery.

Answer 536

A

A. frontopontine.
B. corticobulbar.
C. corticospinal.
D. parietopontine.
E. sympathetic fibers.

The crus cerebri is the anterior portion of the cerebral peduncle, which con- tains motor tracts.

Answer 537

A

A. 11.
B. 10.
C. 9.
D. 8.
E. 7.

The Glasgow Coma Scale (GCS) score is 9. She opens eyes to pain (2) and mumbles sounds (2), and the best motor response is localizing (5). Always take the best motor response when assessing GCS. An intracerebral pressure monitor may not be indicated with a patient who is localizing. The CT brain and neuro exam can guide treatment in this particular patient.

Answer 538

A

A. Glioblastoma multiforme
B. Hemangiopericytoma
C. Ewing’s sarcoma
D. Sinonasal carcinoma metastases
E. Breast carcinoma metastases

(Or C.) Ewing’s sarcoma may present with involvement of the dura, skull, and possibly the underlying parenchyma.

Answer 539

A

A. Glioblastoma multiforme
B. Hemangiopericytoma
C. Ewing’s sarcoma
D. Sinonasal carcinoma metastases
E. Breast carcinoma metastases

This is a calvarial metastases, an occurrence observed not uncommonly with metastatic breast carcinoma.

Answer 540

A

A. Glioblastoma multiforme
B. Hemangiopericytoma
C. Ewing’s sarcoma
D. Sinonasal carcinoma metastases
E. Breast carcinoma metastases

Sinunasal carcinoma may metastasize to multiple dural-based locations.

Answer 541

A

A. Multiple myeloma
B. Recurrence after maximal radiation
C. Multiple lesions at multiple levels
D. Total paralysis for > 48 hours
E. Expected survival < 3 months

B. Recurrence after maximal radiation is an indication to operate

Answer 542

A

A. 20 Gy in 2 Gy fractions over 10 days
B. 30 Gy in 3 Gy fractions over 10 days
C. 60 Gy in 6 Gy fractions over 10 days
D. 100 Gy in 10 Gy fractions over 10 days
E. 200 Gy in 50 Gy fractions over 30 days

Answer 543

A

A. Tetanus
B. Botulism
C. Diphtheria
D. Reye’s syndrome

C. Diphtheria toxin has a predilection to sensory and motor nerves of the limbs
and ciliary muscles or nerves.

Answer 544

A

A. Tetanus
B. Botulism
C. Diphtheria
D. Reye’s syndrome

A. Tetanus may typically present with trismus, risus sardonicus, tonic spasms,
and generalized convulsions.

Answer 545

A

**Botulism*
B. Symptoms appear 12–48 hours after ingestion and may be preceded by nausea, vomiting, and diarrhea. The convergence diffi culty is usually followed by
ptosis and extraocular muscle paralysis

Answer 546

A

D. This is a typical feature of Reye’s syndrome.

Answer 547

A

A. Biopsy-proven plasmacytoma
B. Myeloma cells in a single peripheral blood smear
C. Plasma cells > 10 of 1000 cells on marrow morphology
D. Radiographic survey demonstrating lytic lesions
E. Monoclonal immunoglobulins in the urine or blood

B. Myeloma cells in two or more peripheral blood smears are required

Answer 548

A

A. Hypocalcemia occurs in 25% of patients.
B. Bone pain is characteristically at rest and with movement.
C. There is occurrence of amyloidosis.
D. Invasion of the spinal canal occurs in over 50% of patients.
E. Defi nitive diagnosis can be made by plain X-ray

Patients with spinal multiple myeloma typically present with hypercalcemia,
bone pain characteristically absent at rest, and spinal canal invasion in about
10% of cases. Multiple myeloma (MM) and amyloid light-chain (AL) amyloidosis are caused by the expansion of monoclonal plasma cells and secretion
of dysproteinemia (Bence Jones protein and free light chain)

Answer 549

A

A. Perinervous
B. Arterial
C. Venous
D. Direct extension
E. All of the above

It represents spread via spinal epidural veins. The Batson venous plexus is a network of valveless veins in the human body that connect the deep pelvic veins and thoracic veins to the internal vertebral venous plexuses.

Answer 550

A

C. Facioscapulohumoral dystrophy, or Landouzy-Dejerine’s syndrome is associated with a defect on chromosome 4

Answer 551

A

A. Werdnig-Hoff mann’s disease has autosomal recessive inheritance on chromosome 5q

Answer 552

A

E. Myotonic muscular dystrophy has autosomal dominant inheritance on chromosome 1

Answer 553

A

B. Cri du chat syndrome is due to a 5p deletion and results in microcephaly,
hypertelorism, and congenital heart disease.

Answer 554

A

B. Diltiazem is the preferred agent for patients with systolic heart failure because it produces less myocardial depression than verapamil.

Answer 555

A

A. Verapamil’s side effects include hypotension and worsening of systolic heart
failure due to negative inotropic eff ect.

Answer 556

A

C. Digoxin is indicated for chronic rate control of atrial fi brillation. Because of
its delayed action it is not indicated in acute atrial fi brillation.

Answer 557

A

D. Procainamide is contraindicated in patients with prolonged QT interval because it prolongs QT interval and may be pro-arrhythmic. It is used to convert atrial fi brillation to normal sinus rhyth

Answer 558

A

E. Beta-blockers are indicated for rate control of atrial fibrillation in the setting of a hyperadrenergic state such as acute myocardial infarction after bypass surgery

Answer 559

A

A. ganglioglioma.
B. gliosarcoma
C. glioblastoma multiforme.
D. gliomatosis cerebri.
E. germinoma

Gliosarcoma has the same histological features as glioblastoma multiforme. In addition, it does stain for reticulin in the sarcomatous part of the tumor. Approximately 2% of glioblastomas are gliosarcomas.

Answer 560

A

A. Those with mild neurological defi cits and accessible lesions are better
managed by repair than ligation.
B. Proximal occlusion may be accomplished by an anterior approach with
mobilization of the sternocleidomastoid.
C. Endovascular embolization with detachable balloons may be used for
management.
D. All of the above are true.
E. None of the above are true.

Blunt trauma injuries to the cervical vertebral artery are more often managed by ligation than repair. Ligation may be risky since only ~ 20% of the
general population has a complete collateral circulation. Proximal occlusion
may be accomplished by an anterior approach with mobilization of the sternocleidomastoid. Endovascular treatment with detachable balloons is a valid
option for management

Answer 561

A

C. Arsenic causes peripheral neuropathy, nausea, and vomiting

Answer 562

A

E. Lead causes encephalitis in children as well as pica, irritability, seizures, abdominal cramping, ataxia, coma, and high intracrania

Answer 563

A

B. Manganese causes a Parkinson-like syndrome.

Answer 564

A

A. Mercury causes peripheral neuropathy, cerebellar signs, psychological dysfunctions, tremor, movement disorders, and renal tubular necrosis

Answer 565

A

D. Aluminum may present with a picture of Alzheimer’s disease

Answer 566

A

A. Left atrium
B. Left ventricle
C. Pulmonary veins
D. Aorta
E. Ventricular aneurysms

A. Left atrium accounts for 65–75% of embolisms, mainly the left appendage.
The left ventricle and ventricular aneurysms account for 5% each

Answer 567

A

A. Diabetic ketoacidosis
B. Cushing’s syndrome
C. High intestinal obstruction
D. Chronic diarrhea
E. Uremia

E. Uremia is most likely to cause potassium stores depletion.

Answer 568

A

A. Seizures
B. Tetany
C. Hypotension
D. Loss of deep tendon reflexes
E. Stupor

Tetany is the fi rst sign of magnesium depletion. Delirium occurs usually before convulsions. An increase in deep tendon refl exes is usually observed.

Answer 569

A

A. Na+ 130 mEq/L
B. Cl· 109 mEq/L
C. Lactate 28 mEq/L
D. Ca2+ 16 mEq/L
E. K+ 4 mEq/L

Answer 570

A

A. The male to female ratio is 1.5:1.
B. Thoracic location is the most common.
C. It is usually low grade.
D. It is the most common intramedullary tumor in children.
E. Examination may reveal a combination of upper and lower motor neuron
signs.

The MRI scan demonstrates an intramedullary astrocytoma, which occurs
most commonly in the cervical spine. Lower motor signs may be at the level
of the lesion and may aid in localization. These types of tumors are the most
common intramedullary tumors in children and are usually of fi brillary type.
Intramedullary tumors may be treated empirically with cyberknife radiosurgery with good results forgoing the need for biopsy which can be risky. A
lumbar puncture may be used for an indirect biopsy which is reasonably safe.
It is however low yield but worth a try.

Answer 571

A

A. Amyotrophic lateral sclerosis
B. Systemic lupus erythematosus
C. Metachromatic leukodystrophy
D. Lesch–Nyhan syndrome
E. Niemann–Pick disease

Answer 572

A

A. Amyotrophic lateral sclerosis
B. Systemic lupus erythematosus
C. Metachromatic leukodystrophy
D. Lesch–Nyhan syndrome
E. Niemann–Pick disease

Answer 573

A

A. Amyotrophic lateral sclerosis
B. Systemic lupus erythematosus
C. Metachromatic leukodystrophy
D. Lesch–Nyhan syndrome
E. Niemann–Pick disease

Answer 574

A

A. Increased calcium, normal phosphate, and increased alkaline phosphatase
B. Decreased calcium, increased phosphate, and normal alkaline phosphatase
C. Decreased calcium, decreased phosphate, and increased alkaline
phosphatase
D. Normal calcium, normal phosphate, and increased alkaline phosphatase

Answer 575

A

A. Increased calcium, normal phosphate, and increased alkaline phosphatase
B. Decreased calcium, increased phosphate, and normal alkaline phosphatase
C. Decreased calcium, decreased phosphate, and increased alkaline
phosphatase
D. Normal calcium, normal phosphate, and increased alkaline phosphatase

Answer 576

A

A. Increased calcium, normal phosphate, and increased alkaline phosphatase
B. Decreased calcium, increased phosphate, and normal alkaline phosphatase
C. Decreased calcium, decreased phosphate, and increased alkaline
phosphatase
D. Normal calcium, normal phosphate, and increased alkaline phosphatase

Answer 577

A

A. Increased calcium, normal phosphate, and increased alkaline phosphatase
B. Decreased calcium, increased phosphate, and normal alkaline phosphatase
C. Decreased calcium, decreased phosphate, and increased alkaline
phosphatase
D. Normal calcium, normal phosphate, and increased alkaline phosphatase

Answer 578

A

A. Increased calcium, normal phosphate, and increased alkaline phosphatase
B. Decreased calcium, increased phosphate, and normal alkaline phosphatase
C. Decreased calcium, decreased phosphate, and increased alkaline
phosphatase
D. Normal calcium, normal phosphate, and increased alkaline phosphatase

Answer 579

A

A. Chronic respiratory acidosis
B. Non-anion gap metabolic acidosis and respiratory alkalosis
C. Metabolic alkalosis and respiratory acidosis
D. Wide anion gap metabolic acidosis
E. Chronic respiratory alkalosis

Answer 580

A

A. Chronic respiratory acidosis
B. Non-anion gap metabolic acidosis and respiratory alkalosis
C. Metabolic alkalosis and respiratory acidosis
D. Wide anion gap metabolic acidosis
E. Chronic respiratory alkalosis

Answer 581

A

A. Chronic respiratory acidosis
B. Non-anion gap metabolic acidosis and respiratory alkalosis
C. Metabolic alkalosis and respiratory acidosis
D. Wide anion gap metabolic acidosis
E. Chronic respiratory alkalosis

Answer 582

A

A. Chronic respiratory acidosis
B. Non-anion gap metabolic acidosis and respiratory alkalosis
C. Metabolic alkalosis and respiratory acidosis
D. Wide anion gap metabolic acidosis
E. Chronic respiratory alkalosis

Answer 583

A

A. Chronic respiratory acidosis
B. Non-anion gap metabolic acidosis and respiratory alkalosis
C. Metabolic alkalosis and respiratory acidosis
D. Wide anion gap metabolic acidosis
E. Chronic respiratory alkalosis

Here are some pointers in interpreting the arterial blood gas: The most useful information comes from the clinical description of the patient by the history and physical examination; however in this case this information is not
given. Therefore, the next step is to look at the pH. If pH < 7.35, then there is
an acidemia; if pH > 7.45, then there is an alkalemia. The pH may be normal
in the presence of a mixed acid base disorder, particularly if other parameters of the ABG are abnormal. The third step is to look at PCO2 and HCO3- in
order to determine the acid base process (alkalosis vs. acidosis) leading to the
abnormal pH. In simple acid base disorders, both values are abnormal and
direction of the abnormal change is the same for both parameters. One abnormal value will be the initial change and the other will be the compensatory response. Once the initial change is identifi ed, then the other abnormal
parameter is the compensatory response if the direction of the change is the
same. If not, suspect a mixed disorder. Once the initial chemical change and
the compensatory response is distinguished, then identify the specifi c disorder. If PCO2 is the initial chemical change, then the process is respiratory; if
HCO3- is the initial change, then the process is metabolic.
Below is a brief description of the initial chemical change followed by the
compensatory response in basic acid/base disorders:
Respiratory Acidosis
PCO2
HCO3-
Respiratory Alkalosis
PCO2
HCO3-
Metabolic Acidosis
HCO3-
PCO2
Metabolic Alkalosis
HCO3-
PCO2

Answer 584

A

A. Scan 1
B. Scan 2
C. Scans 1 and 2
D. None of the above

Answer 585

A

A. Scan 1
B. Scan 2
C. Scans 1 and 2
D. None of above

Answer 586

A

A. Scan 1
B. Scan 2
C. Scans 1 and 2
D. None of the above

Answer 587

A

A. the tuberoinfundibular nucleus.
B. the preoptic nucleus.
C. the paraventricular nucleus.
D. the mammillary bodies.
E. None of the above

B. The preoptic nucleus is considered part of the anterior hypothalamus.

Answer 588

A

A. Adie’s pupil
B. Posterior communicating artery aneurysm
C. Kennedy syndrome
D. Horner’s syndrome
E. Third nerve lesion

C. All the other choices result in an eff erent defect.

Answer 589

A

A. Macular degeneration
B. Optic neuritis
C. Papilledema
D. Metabolic optic neuropathy
E. Retinal lesion

.D. Metabolic neuropathy is typically symmetric and bilateral and will rarely
present with an aff erent pupillary defect clinically

Answer 590

A

A. Decreasing the positive end expiratory pressure to 0 cm H2O
B. Hyperventilation
C. Improving mixed venous oxygen contents
D. Oxygen supplementation
E. None of the above

An improvement in mixed venous oxygen contents will often improve the
hypoxemia in the setting of a shunt.

Answer 591

A

A. 96 hours.
B. 72 hours.
C. 48 hours.
D. 24 hours.
E. 12 hours

The half-life is 72 hours.

Answer 592

A

A. Conversion of prothrombin to thrombin
B. Activation of contact factors
C. Generation of thromboplastin
D. Release of phospholipids from platelets
E. Conversion of fi brinogen to fi brin

Conversion of prothrombin from thrombin is the most time consuming and is usually measured as the prothrombin time (PT); it is in the range of 11 to 13 seconds.

Answer 593

A

B.

The second fi gure shows a venous angioma which can be caused by arrested development.

Answer 594

A

D

Dural arteriovenous malformations are usually acquired after dural thrombosis. Neither cavernous malformation (fi rst image) nor venous angioma (second image) is an acquired lesion

Answer 595

A

B

Blue rubber nevus syndrome is associated with venous angiomas

Answer 596

A

A. Ocular bobbing
B. Jerk nystagmus
C. See-saw nystagmus
D. Downbeat nystagmus
E. None of the above

Answer 597

A

A. Ocular bobbing
B. Jerk nystagmus
C. See-saw nystagmus
D. Downbeat nystagmus
E. None of the above

Answer 598

A

A. Ocular bobbing
B. Jerk nystagmus
C. See-saw nystagmus
D. Downbeat nystagmus
E. None of the above

Answer 599

A

A. Ocular bobbing
B. Jerk nystagmus
C. See-saw nystagmus
D. Downbeat nystagmus
E. None of the above

Answer 600

A

.B. The glomerulus is formed by the Golgi cell, the granule cell, and the mossy
fiber.

Answer 601

A

A. The granule cell is the only excitatory cell within the cerebellum

Answer 602

A

D. Basket cells end in a rete of terminals around the Purkinje cell

Answer 603

A

C. Purkinje cells synapse with the deep cerebellar nuclei

Answer 604

A

A. Blurred vision
B. Diaphoresis
C. Apnea
D. Hallucinations
E. Sneezing

Early signs of cyanide poisoning include general weakness, malaise, early giddiness, inebriation, confusion, headache, vertigo, dizziness, confusion, and hallucinations. Tachypnea and hyperpnea generally precede apnea

Answer 605

A

A. Manganese
B. Zinc
C. Iron
D. Copper
E. All of the above

All are important in wound healing. Zinc is a mineral that is important for the action of collagenase. Manganese is necessary for the glycosylation of hydroxyproline residues in the formation of collagen. Copper is a cofactor of ceruloplasmin and is involved in the synthesis of oxidative metalloenzymes and elastics. Iron is a vital cofactor for proteins and enzymes involved in energy metabolism, respiration, DNA synthesis, cell cycle arrest, and apoptosis

Answer 606

A

A. inhibition of DNA synthesis.
B. cell membrane destruction.
C. cell wall damage.
D. inhibition of protein synthesis.
E. None of the above

Aminoglycosides act by inhibiting protein synthesis through irreversible ribosomal attachment. Examples of aminoglycoside antibiotics are amikacin,
tobramycin, gentamicin, streptomycin, and neomycin

Answer 607

A

A. Streptomycin
B. Kanamycin
C. Neomycin
D. Polymyxin
E. Gentamicin

Polymyxin does not cause neuromuscular blockade.

Answer 608

A

A. The Allcock test is useful.
B. External ventricular drainage following subarachnoid hemorrhage from
this type of aneurysm is an accepted temporizing treatment.
C. Proximal ligation is the preferred treatment.
D. Vasospasm in this area is unlikely to cause respiratory compromise.
E. A lumbar drain is contraindicated in this case.

The image represents a vertebral artery aneurysm. The preferred treatment is direct aneurysm clipping of this aneurysm. The Allcock test will test patency of the circle of Willis via carotid occlusion. Vasospasm in this area can cause midbrain and medullary syndrome, including respiratory arrest and neurogenic pulmonary edema. A lumbar arachnoid catheter may also be used to allow CSF drainage

Answer 609

A

A. The dura needs to be opened at either end well above the lesion.
B. Dilated veins are more likely to be encountered at the rostral end of the
mass.
C. Myelotomy is to be done as close to the midline as possible.
D. Intracapsular decompression of the tumor is necessary to avoid any
traction.
E. C-arm guidance for localization may be helpful.

When removing an intramedullary spinal cord tumor one is more likely to encounter dilated veins at the caudal end of the mass. The other points are general principles of spinal cord tumor resection. Note that it is useful to seek out the blood supply of the tumor before debulking to keep the fi eld relatively free of blood

Answer 610

A

A. sulfatides.
B. galactocerebroside.
C. ganglioside.
D. long-chain fatty acids.
E. None of the above

Galactocerebroside accumulates in Krabbe’s disease. Ganglioside accumulates in Tay–Sachs’s and Sandhoff ’s diseases. Long chain fatty acids accumulate in adrenoleukodystroph

Answer 611

A

A. fl exor response as seen in decerebrate rigidity.
B. crossed extensor refl ex.
C. monosynaptic stretch refl ex.
D. supramaximal stimulation of a mixed motor-sensory nerve.
E. All of the above

The T-refl ex represents the monosynaptic stretch refl ex elicited by tapping a tendon

Answer 612

A

A. lower pons.
B. upper pons.
C. lower midbrain.
D. upper midbrain.
E. medulla

The trochlear nerve arises at the level of the lower midbrain (inferior colliculus level

Answer 613

A

A. opsoclonus.
B. increased glutamic acid decarboxylase.
C. anti–Purkinje cell antibodies.
D. presynaptic acetylcholine receptor disorder.
E. multiple sclerosis

The patient likely has Lambert–Eaton myasthenic syndrome (LEMS) with
small cell (oat cell) carcinoma. About 60% of those with LEMS have an underlying malignancy, most commonly small cell lung canc

Answer 614

A

A. 50 mEq
B. 150 mEq
C. 350 mEq
D. 500 mEq
E. 1000 mEq

Total body potassium excess of 100 to 200 mEq is required to produce a rise of 1 mEq/L in serum potassium

Answer 615

A

A. Lateral cord
B. Ulnar nerve
C. Musculocutaneous nerve
D. Median nerve
E. Lower subscapular nerve

he ulnar nerve has no supply from the C6 root.

Answer 616

A

B. Cervical roots C2 and C3 innervate this muscle

Answer 617

A

D. Involved in the phrenic nerve and the brachial plexus.

Answer 618

A

C. Innervated by the obturator nerve (L2, L3).

Answer 619

A

D. Innervated by C3, C4 (cervical nerves) and C5 (dorsal scapular nerve which
arises from the brachial plexus).

Answer 620

A

E. Innervated by the pudendal nerve (S2–S4).

Answer 621

A

B. Innervated by the accessory nerve and C2 roots

Answer 622

A

A. Hallucinations while sleeping
B. Convulsions while sleeping
C. Daytime hyperalertness
D. NREM onset of sleep
E. Gelastic seizures

Hypnagogic hallucinations are seen with narcolepsy. Hypnagogic or hypnopompic hallucinations are visual, tactile, auditory, or other sensory events, usually brief but occasionally prolonged, that occur at the transition from wakefulness to sleep (hypnagogic) or from sleep to wakefulness (hypnopompic). People with narcolepsy have a reduced number of neurons that produce the protein orexin-A

Answer 623

A

A. Thiamine
B. B6
C. Cobalamine
D. Niacin
E. Vitamin A

Answer 624

A

A. Thiamine
B. B6
C. Cobalamine
D. Niacin
E. Vitamin A

Answer 625

A

A. Thiamine
B. B6
C. Cobalamine
D. Niacin
E. Vitamin A

Answer 626

A

A. Thiamine
B. B6
C. Cobalamine
D. Niacin
E. Vitamin A

Answer 627

A

A. Type A GABA agonist
B. Type B GABA agonist
C. GABA antagonist
D. No eff ect on GABA receptors

Answer 628

A

A. Type A GABA agonist
B. Type B GABA agonist
C. GABA antagonist
D. No eff ect on GABA receptors

Answer 629

A

A. Type A GABA agonist
B. Type B GABA agonist
C. GABA antagonist
D. No eff ect on GABA receptors

Answer 630

A

A. Type A GABA agonist
B. Type B GABA agonist
C. GABA antagonist
D. No eff ect on GABA receptors

Answer 631

A

A. anterior communicating and superior hypophyseal.
B. basilar and anterior communicating.
C. PICA and superior hypophyseal.
D. PICA and basilar.
E. basilar and posterior communicating.

The two aneurysms are a calcifi ed thrombotic basilar artery aneurysm and a posterior communicating artery aneurysm.

Answer 632

A

A. A common presenting sign is papilledema.
B. It arises from the diencephalic recess of the postvellar arch.
C. Risk of sudden death is attributable to CSF dynamics or disturbances in
hypothalamic-related cardiovascular control.
D. Lumbar puncture is part of the initial workup.
E. The patient may require a shunt postoperatively

The lesion presented is a colloid cyst of the third ventricle. A lumbar puncture is contraindicated prior to the placement of a shunt or a ventricular
catheter due to the risk of herniation.

Answer 633

A

A. Phasic changes of amplitude and polarity of ventricular complexes
B. Hypokalemia
C. Hypomagnesemia
D. Narrowed QT intervals
E. May be predisposed by erythromycin

Torsades de pointes presents with prolonged QT intervals.

Answer 634

A

A. In early ARDS, the hypoxemia is more pronounced and the chest X-ray
abnormalities are more evident.
B. In early ARDS, the hypoxemia is less pronounced and the chest X-ray abnormalities are more evident.
C. In early ARDS, the hypoxemia is more pronounced and the chest X-ray
abnormalities are less evident.
D. In early ARDS, the hypoxemia is less pronounced and the chest X-ray abnormalities are less evident.
E. None of the above

In early ARDS, the chest X-ray may be unrevealing, whereas the patient may
present with a hypoxemia refractory to supplemental oxygen

Answer 635

A

A. Insulin
B. Alkali therapy
C. Potassium
D. Crystalloids
E. Phosphate

Bicarbonate therapy does not improve outcome in diabetic ketoacidosis, regardless of the severity of the acido

Answer 636

A

A. metastasis.
B. hemangioblastoma.
C. glioma.
D. central nervous system (CNS) lymphoma.
E. pilocytic astrocytoma

The MRI shows an enhancing mural nodule with an associated cyst. Pathology shows highly vascular tissue and stromal cells characteristic of hemangioblastoma

Answer 637

A

A. glioblastoma multiforme resection.
B. radiation therapy.
C. trauma.
D. encephalitis.
E. cerebral atrophy

This T2-weighted MRI shows enhancement of the medial temporal lobe, a finding representative of herpes encephalitis

Answer 638

A

A. deep peroneal nerve.
B. superfi cial peroneal nerve.
C. common peroneal nerve.
D. sciatic nerve.
E. tibial nerve.

The superfi cial peroneal nerve innervates the peroneus longus and brevis, which evert the foot. A lesion of the deep peroneal nerve will aff ect ankle dorsifl exion. A lesion of the common peroneal or sciatic nerves will aff ect both ankle dorsifl exion and foot eversion. A sciatic nerve lesion will also affect foot fl exion and inversion

Answer 639

A

A. the trunk.
B. the branch.
C. the cord.
D. the root.
E. None of the above

The order of the brachial plexus structures is: root, trunk, division, cord, and
branch.

Answer 640

A

A. Defi nitive clipping, temporary clipping, fi ssure splitting, dissection of M2 branch from dome
B. Dissection of M2 branch from dome, fi ssure splitting, temporary clipping, defi nitive clipping
C. Fissure splitting, temporary clipping, dissection of M2 branch from dome, defi nitive clipping
D. Temporary clipping, fi ssure splitting, dissection of M2 branch from dome, defi nitive clipping
E. Fissure splitting, dissection of M2 branch from dome, temporary clipping, defi nitive clipping

Fissure splitting, temporary clipping, dissection of M2 branch from dome, and defi nitive clipping is the proper order of steps for clipping this difficult aneurysm

Answer 641

A

A. Overexpression of CDK4
B. Deletion of p53
C. Mutation of retinoblastoma
D. Amplifi cation of K-ras
E. Overexpression of CDK6

Aberrations of genes coding for cell cycle regulatory proteins involved in the control of G1/S phase transition have been found in gliomas and include mutation or deletion of genes like p53, retinoblastoma, cyclic AMP-dependent kinase number 2 (CDKN2) A/B, and amplifi cation or overexpression of CDK4 and CDK6

Answer 642

A

A. 1p
B. 7
C. 9p
D. 19q
E. 22

Oligodendrogliomas may exhibit loss of chromosomal regions on 1p and 19q13. Other chromosomal regions that may be lost from oligodendrogliomas are 1p36, 9p, and 22. There may be evidence of increased numbers of
chromosome 7

Answer 643

A

A. Stellate ganglionectomy is used in the treatment of long QT syndrome.
B. Anhydrosis occurs with ganglionectomy.
C. Each intercostal nerve is connected to the sympathetic trunk by at leastone white ramus and two gray rami.
D. The inferior hypogastric plexus lies in front of the promontory of the sacrum between the two common iliac arteries and is sometimes called
the presacral nerve.
E. Sympathetically conveyed stimulus to the sweat glands is transmitted by acetylcholine

The superior hypogastric plexus lies in front of the promontory of the sacrum between the two common iliac arteries and is sometimes called the presacral nerve. It then divides into the right and left inferior hypogastric plexuses

Answer 644

A

A. Cingulate gyrus
B. Hippocampus
C. Amygdala
D. Mammillary bodies
E. Anterior nucleus of the thalamus

Answer 645

A

A. Cingulate gyrus
B. Hippocampus
C. Amygdala
D. Mammillary bodies
E. Anterior nucleus of the thalamus

Answer 646

A

A. Cingulate gyrus
B. Hippocampus
C. Amygdala
D. Mammillary bodies
E. Anterior nucleus of the thalamus

The circuit of Papez includes the cingulate gyrus, hippocampus, mammillary bodies, and anterior nucleus of the thalamus. The lateral parabrachial nucleus of the amygdala receives inputs from the lateral olfactory tract, pyriform cortex, hypothalamus, paraventricular thalamus, and solitary tract nucleus. The medial septal nucleus projects to the fi mbria to the hippocampus

Answer 647

A

A. Amyotrophic lateral sclerosis (ALS)
B. Huntington’s disease
C. Acute respiratory distress syndrome
D. AIDS
E. Multiple sclerosi

Answer 648

A

A. Congestive heart failure
B. Pulmonary hypertension
C. Renal failure
D. Microcephaly
E. Subarachnoid hemorrhage

Answer 649

A

A. The most common location is cervicothoracic.
B. The presence of a malignancy is a predisposing condition.
C. There is increased incidence with epidural anesthesia.
D. The incidence is 1:10,000 in the United States.
E. There is increased incidence with drug abuse

Answer 650

A

A. antibiotic therapy.
B. diuretics.
C. secretory diarrhea.
D. diabetes mellitus.
E. dilantin therapy.

Urinary magnesium loss is most prominent with loop diuretics

Answer 651

A

A. Jugular
B. Nodose
C. Pterygopalatine
D. Ciliary
E. Superior cervical

The superior salivatory nucleus sends axons via the nervus intermedius (VII)
to the greater superfi cial petrosal nerve and then to the pterygopalatine
ganglion

Answer 652

A

A. Jugular
B. Nodose
C. Pterygopalatine
D. Ciliary
E. Superior cervical

The oculomotor nerve (III) carries parasympathetics from Edinger–Westphal’s nucleus to the ciliary ganglion

Answer 653

A

A. Jugular
B. Nodose
C. Pterygopalatine
D. Ciliary
E. Superior cervical

Arnold’s nerve is a branch of the vagus nerve (X) supplying sensation to the dura of the posterior fossa

Answer 654

A

A. Jugular
B. Nodose
C. Pterygopalatine
D. Ciliary
E. Superior cervical

The deep petrosal nerve carries sympathetic fi bers from the internal carotid artery from the superior cervical ganglion

Answer 655

A

A. Loss of sensation to the outer ear
B. Loss of taste on the tongue surface
C. Loss of salivatory secretion from a gland
D. Weakness of the pharynx
E. Strength of facial muscles

Both nerves contain sensory inputs from the outer ear. The glossopharyngeal nerve controls elevation of the pharynx, whereas the facial nerve has no actions on pharyngeal mus

Answer 656

A

A. dopamine.
B. dobutamine.
C. neosinephrine.
D. epinephrine.
E. isoproterenol

Dobutamine is an adrenergic agent that does not cause peripheral vasoconstriction.

Answer 657

A

A. cyanide.
B. thiocyanate.
C. nitric oxide.
D. thiosulfate.
E. vitamin B12

Thiocyanate is cleared by the kidneys and its accumulation with the use of nitroprusside may cause a toxic syndrome

Answer 658

A

B. Single punched out lesion without sclerotic edges is typical

Answer 659

A

B. Eosinophilic granuloma may be a monostotic form of Langerhans cell
histiocytosis.

Answer 660

A

C. In Paget’s disease, one may observe bony destruction (early) and sclerosis
(late).

Answer 661

A

A. Albright’s syndrome is characterized by unilateral fi brous dysplasia,
pigmented skin lesions, and precocious puberty.

Answer 662

A

D. Epidermoid has characteristic scalloped edges

Answer 663

A

A. Pneumocystis carinii pneumonia.
B. cytomegalovirus infections.
C. toxoplasmosis.
D. AIDS encephalitis.
E. hydrocephalus.

Pneumocystis carinii pneumonia is the most common cause of ICU admission in HIV-positive patients. It is usually treated with trimethoprim-sulfamethoxazole. Toxoplasma is the most common intracranial infection in HIV-positive patient

Answer 664

A

A. 9%.
B. 0.9%.
C. 0.09%.
D. 0.009%.
E. 0.0009%

There are 9 cases of transmission for every 10,000 exposures. It is advisable to wear two pairs of gloves at surgery and to replace the top pair every 90 minutes of arduous surgery

Answer 665

A

A. Chordoma
B. Epidermoid
C. Basilar tip aneurysm
D. Arachnoid cyst
E. Low-grade glioma

The lesion most likely represents a lobulated arachnoid cyst. An aneurysm would not display such septations.

Answer 666

A

A. Golgi organelle
B. Endoplasmic reticulum
C. Both A and B
D. None of the above

Answer 667

A

A. Golgi organelle
B. Endoplasmic reticulum
C. Both A and B
D. None of the above

The Golgi organelle possesses enzymes that are important in sugar and lipid chemistry of the eukaryotic cell.

Answer 668

A

A. Golgi organelle
B. Endoplasmic reticulum
C. Both A and B
D. None of the above

The endoplasmic reticulum is important in drug detoxifi cation; for example, adding hydroxyl groups to a lipid soluble–type compound makes it more water soluble and thus easier to remove from the

Answer 669

A

A. Golgi organelle
B. Endoplasmic reticulum
C. Both A and B
D. None of the above

Glycogen formation and breakdown occur in the endoplasmic reticulum; this
is particularly important in the liver. Glycogen, a polymer of glucose-1-phosphate, represents a quick source of energy.

Answer 670

A

A. Golgi organelle
B. Endoplasmic reticulum
C. Both A and B
D. None of the above

Both the Golgi membranes closest to the nucleus (forming face) and the endoplasmic reticulum have a lamellar or tube-like membranous system. The Golgi membranes away from the nucleus (maturing face) are much more like plasma or organelle membranes

Answer 671

A

A. Accumulates in neurons of the substantia nigra
B. Found in the locus ceruleus
C. Made by tyrosinase
D. Is a cathecholamine waste product
E. Chelates metal ions such as aluminum and iron

True melanin is made by tyrosinase. Tyrosinase is an oxidase that is the rate-limiting enzyme for controlling the production of melanin. Neuromelanin is biosynthesized from L-dopa by tyrosine hydroxylase and aromatic acid decarboxylase.

Answer 672

A

A. Nucleus accumbens
B. Pyriform cortex
C. Solitary tract nucleus
D. Locus ceruleus
E. Prefrontal cortex

he amygdala sends eff erents to the nucleus accumbens via the amygdalostriate fi bers. All others are aff erent sources to the amygdala.

Answer 673

A

A. Hypercapnia
B. Acalculous cholecystitis
C. Impaired oxygenation
D. Calculous cholecystitis
E. Increased incidence of infection

Total parenteral nutrition has been known to cause hypercapnia due to excessive carbohydrates promoting carbon dioxide retention, impaired oxygenation due to fatty acid damage to pulmonary capillaries, and acalculous cholecystitis due to bile stasis secondary to absence of lipids in the proximal small bowel

Answer 674

A

A. May have elevated carcinoembryonic antigen (CEA) levels
B. Associated with Schiller–Duval bodies
C. Derived from extraembryonic tissue
D. Ingestion of food with fecal contamination
E. Multiple sclerosis

This scan shows a teratoma, which is associated with elevation of CEA levels

Answer 675

A

A. Anti-Yo antibodies
B. Anti-Hu antibodies
C. Anti-Ri antibodies
D. Antibodies to presynaptic voltage-gated receptors
E. None of the above

Paraneoplastic sensory neuropathy with anti-Hu antibodies is associated with limbic encephalitis (as seen on this MRI scan), seizures, epilepsia partialis continua, cerebellar ataxia, autonomic instability, myelitis with patchy weakness, and brainstem encephalitis.

Answer 676

A

A. 40-year-old man with chronic encephalitis and Argyll Robertson pupils
B. 15-year-old hyperglycemic with severe lower extremity weakness
C. 55-year-old man with spastic gait, weakness, and fasciculation in all
extremities
D. 4-year-old boy with bilateral symmetric proximal limb weakness
E. 60-year-old female with spondylolisthesis at L5–S1

Answer 677

A

A. Respiratory acidosis
B. Respiratory alkalosis
C. Both
D. Neither

Answer 678

A

A. Respiratory acidosis
B. Respiratory alkalosis
C. Both
D. Neither

Answer 679

A

A. Respiratory acidosis
B. Respiratory alkalosis
C. Both
D. Neither

Answer 680

A

A. Respiratory acidosis
B. Respiratory alkalosis
C. Both
D. Neither

Massive pulmonary embolism can result in signifi cant increased dead space and respiratory acidosis; on the other hand, smaller pulmonary embolisms can present with hyperventilation and hence respiratory alkalosis. Liver cirrhosis may also cause hyperventilation. Aminoglycosides can be presynaptic at the neuromuscular junction, causing respiratory acidosis.

Answer 681

A

A. Water diff usion is hindered anteriorly by the presence of a large tumor.
B. Connections between frontal and occipital lobe are impaired on the right side.
C. There are intersecting white matter tracts between the splenium and the
fronto-occipital tracts.
D. Tractography gives information about the direction of fl ow.
E. Bundles of axons provide a barrier to perpendicular diff usion and a path
for parallel diff usion along the orientation of the fi bers

Tractography is a procedure to demonstrate the neural tracts. It uses special techniques of magnetic resonance imaging (MRI), and computer postprocessing. Information about direction of fl ow is provided by tractography
but not about connections between diff erent structures in the brain

Answer 682

A

A. It is associated with dermal sinus tract.
B. It secretes histamine.
C. On histopathology, one may see densely packed elongated spindle cells in
interlocking fascicles with a tendency toward palisading.
D. All of the above are true.
E. None of the above are true.

The scan shows an atypical dermoid cyst. Dermoid cysts can contain fat
which gives them high signal intensity on T1-weighted sequences. A congenital dermal sinus tract can be associated with a dermoid cyst. Choice B is associated with paraganglioma. Choice C is representative of Antoni A pattern
in acoustic neuromas

Answer 683

A

A. Abnormality in protein merlin
B. Posterior capsular lens opacities
C. Intertriginous freckling
D. Pigmented area of skin with excess hair
E. May be associated with an autosomal disorder located on chromosome 22

The MRI scan shows bilateral acoustic neuromas, pathognomonic of neurofibromatosis type 2. Intertriginous freckling is a feature of neurofi bromatosis type 1.

Answer 684

A

A. Amphotericin B
B. Lithium
C. Toluene
D. Carbonic anhydrase inhibitors
E. Cyclamate

Carbonic anhydrase inhibitors (e.g., acetazolamide) can cause proximal renal tubular acidosis.

Answer 685

A

A. Hydrocortisone sodium succinate (Solucortef) for glucocorticoid
emergencies
B. Fludrocortisone (Florinef) for mineralocorticoid emergencies
C. Methylprednisolone (Solumedrol) for glucocorticoid emergencies
D. Cortisone acetate for glucocorticoid emergencies
E. Intravenous fl uids

Methylprednisolone is not recommended in the treatment of emergent Addisonian crisis. Long-term use of methylprednisolone can cause Addisonian
crisis if stopped abruptly and not tapered.

Answer 686

A

A. furosemide.
B. phenytoin.
C. lithium.
D. All of the above
E. None of the above

All three medications have been shown to help in the treatment of syndrome of inappropriate antidiuretic hormone (SIADH), with variable side-eff ect patterns

Answer 687

A

A. B and O plasma types
B. B and AB plasma types
C. B plasma type only
D. All of the above
E. None of the above

Plasma types B and O can be safely transfused in a patient with blood type B because both of these plasma types do not contain antibodies against B type blood.

Answer 688

A

A. Increased arteriolar tone
B. Increased in peripheral vascular resistance
C. Cool molten skin
D. Hypertension
E. Bradycardia

Neurogenic shock is characterized by dilatation of arterioles and venules and decreased peripheral vascular resistance. It also presents with warm, dry skin, bradycardia, and hypotension

Answer 689

A

A. urinary tract infection.
B. pneumonia.
C. wound infection.
D. gastrointestinal infection.
E. pressure ulcers.

The urinary system is the most commonly involved in patients with
gram-negative septicemia, followed by the respiratory system

Answer 690

A

A. Latex agglutination test
B. Tissue culture assay for cytotoxin
C. Stool culture
D. Stool microscopy
E. Polymerase chain reaction (PCR) analysis

Stool culture has a sensitivity of > 90% in diagnosing C. diffi cile enterocolitis.
Both latex agglutination and tissue culture assay for cytotoxin have a sensitivity of ~ 70%. Stool microscopy is not used to diagnose this co

Answer 691

A

A. Isoflurane
B. Enflurane
C. Thiopental
D. Halothane

Halothane increases cerebral blood fl ow the most followed by enfl urane and isofurane.

Answer 692

A

A. Isoflurane
B. Enflurane
C. Thiopental
D. Halothane

Thiopental decreases intracranial pressure. The other listed agents will increase intracranial pressure.

Answer 693

A

A. Isoflurane
B. Enflurane
C. Thiopental
D. Halothane

Isofurane has been shown to cause tachycardia transiently in children

Answer 694

A

A. Isoflurane
B. Enflurane
C. Thiopental
D. Halothane

Enfurane increases systemic vascular resistance. Isofurane will decrease it

Answer 695

A

A. Neurofi bromatosis type 1 (NF1)
B. Neurofi bromatosis type 2 (NF2)
C. Both A and B
D. None of the above

C. Both NF1 and NF2 have autosomal dominant patterns of inheritance

Answer 696

A

A. Neurofi bromatosis type 1 (NF1)
B. Neurofi bromatosis type 2 (NF2)
C. Both A and B
D. None of the above

Answer 697

A

A. Neurofi bromatosis type 1 (NF1)
B. Neurofi bromatosis type 2 (NF2)
C. Both A and B
D. None of the above

Answer 698

A

A. Neurofi bromatosis type 1 (NF1)
B. Neurofi bromatosis type 2 (NF2)
C. Both A and B
D. None of the above

Answer 699

A

A. The neck of the aneurysm is unobstructed.
B. The neck of the aneurysm is obstructed by the dome.
C. The neck of the aneurysm is obstructed by the optic nerve.
D. The neck of the aneurysm is obstructed by the carotid artery.
E. The neck of the aneurysm is obstructed by the anterior clinoid process

Answer 700

A

A. Superior cerebellar artery, abducens nerve
B. Anterior inferior cerebellar artery, trochlear nerve
**C. Superior cerebellar artery, trochlear nerve
**D. Anterior inferior cerebellar artery, abducens nerve
E. Superior cerebellar artery, oculomotor nerve

Answer 701

A

A. Supracerebellar infratentorial approach for cyst resection
B. Midline frontal approach for cyst resection
C. Third ventriculostomy
D. Midline frontal approach for cyst decompression
E. Endoscopic cyst resection

Answer 702

A

A. Meperidine
B. Thyroid hormones
C. Fluconazole
D. Papaverine

Answer 703

A

A. Meperidine
B. Thyroid hormones
C. Fluconazole
D. Papaverine

Answer 704

A

A. Meperidine
B. Thyroid hormones
C. Fluconazole
D. Papaverine

Answer 705

A

A. Meperidine
B. Thyroid hormones
C. Fluconazole
D. Papaverine

Answer 706

A

A. Meperidine
B. Thyroid hormones
C. Fluconazole
D. Papaverine

Papaverine inhibits antiparkinsonian eff ect of levodopa. Fluconazole increases serum phenytoin and decreases warfarin metabolism. Thyroid hormones
enhance clotting factor catabolism. Meperidine may cause hypertension, rigidity, and excitation when used with monoamine oxidase inhibitors

Answer 707

A

A. Epinephrine
B. Isoflurane
C. Halothane
D. Thiopental
E. All of the above

Answer 708

A

A. Lung carcinoma
B. Breast carcinoma
C. Colon carcinoma
D. Renal cell carcinoma
E. Prostate carcinoma

Answer 709

A

A. Brachiocephalic artery
B. Axillary artery
C. Subcalvian artery
D. Brachial artery
E. Internal carotid artery

The lateral, medial, and posterior cords carry their names in relation to the second and third segments of the axillary artery

Answer 710

A

A. Traumatic
B. Degenerative
C. Isthmic
D. Pathological
E. Dysplastic

This type of spondylolisthesis is caused by a defect in the pars interarticularis, occurs in 90% of cases at L5–S1, and is usually bilateral and more common
in males

Answer 711

A

A. Homonymous hemianopia
B. Upper homonymous quadrantanopia
C. Bilateral central scotomas
D. Monocular loss of vision with contralateral upper outer quadrantanopia
E. Lower homonymous quadrantanopia

Answer 712

A

A. Homonymous hemianopia
B. Upper homonymous quadrantanopia
C. Bilateral central scotomas
D. Monocular loss of vision with contralateral upper outer quadrantanopia
E. Lower homonymous quadrantanopia

Answer 713

A

A. Homonymous hemianopia
B. Upper homonymous quadrantanopia
C. Bilateral central scotomas
D. Monocular loss of vision with contralateral upper outer quadrantanopia
E. Lower homonymous quadrantanopia

Answer 714

A

A. Homonymous hemianopia
B. Upper homonymous quadrantanopia
C. Bilateral central scotomas
D. Monocular loss of vision with contralateral upper outer quadrantanopia
E. Lower homonymous quadrantanopia

Answer 715

A

A. Homonymous hemianopia
B. Upper homonymous quadrantanopia
C. Bilateral central scotomas
D. Monocular loss of vision with contralateral upper outer quadrantanopia
E. Lower homonymous quadrantanopia

Answer 716

A

A. Homonymous hemianopia
B. Upper homonymous quadrantanopia
C. Bilateral central scotomas
D. Monocular loss of vision with contralateral upper outer quadrantanopia
E. Lower homonymous quadrantanopia

Answer 717

A

A. Struthers ligament
B. Arcade of Struthers
C. Arcade of Frohse
D. Guyon’s canal

Answer 718

A

A. Struthers ligament
B. Arcade of Struthers
C. Arcade of Frohse
D. Guyon’s canal

Answer 719

A

A. Struthers ligament
B. Arcade of Struthers
C. Arcade of Frohse
D. Guyon’s canal

Answer 720

A

A. Reservoir sign
B. Early morning headache
C. Meningitis
D. Visual defi cits
E. Sinus congestion

Answer 721

A

A. Radicular pain
B. Scoliosis
C. Weakness
D. Atrophy
E. None of the above

Scoliosis occurs in 66%, whereas radicular pain occurs in 50% of patients

Answer 722

A

A. Radicular pain
B. Scoliosis
C. Weakness
D. Atrophy
E. Cardiac ischemia

Weakness occurs in 51%, whereas radicular pain occurs in 44% and scoliosis
in 36% of patients.

Answer 723

A

A. 1, 2, and 3
B. 1 and 3
C. 2 and 4
D. 1, 2, 3, and 4
E. 2 and 3

Answer 724

A

A. It is caused by frequent repetitive motion at the wrist.
B. Pain and tenderness occurs in the wrist near the thumb.
C. The Finkelstein test is positive.
D. Nerve conduction velocities are decreased.
E. There is diffi culty with gripping.

De Quervain’s syndrome is characterized by tenosynovitis of the abductor
pollicis longus and extensor pollicis brevis muscles. The nerve conduction
velocities are typically normal

Answer 725

A

B

The roof of the fourth ventricle contains both the superior and inferior medullary veli. The fl oor of the fourth ventricle is formed by the rhomboid fossa,
which contains the facial colliculus and hypoglossal trigone

Answer 726

A

A. Surgical evacuation
B. Systemic antibiotics
C. Head wrapping
D. Radiation therapy
E. VP shunt

Answer 727

A

A. Basal plate
B. Notochord
C. Neural crest cells
D. Somites
E. Endoderm

Answer 728

A

A. Cheyne–Stokes respiration
B. Apneustic respiration
C. Ataxic respiration
D. Central neurogenic hyperventilation

Answer 729

A

A. Cheyne–Stokes respiration
B. Apneustic respiration
C. Ataxic respiration
D. Central neurogenic hyperventilation

Answer 730

A

A. Cheyne–Stokes respiration
B. Apneustic respiration
C. Ataxic respiration
D. Central neurogenic hyperventilation

Answer 731

A

A. Cheyne–Stokes respiration
B. Apneustic respiration
C. Ataxic respiration
D. Central neurogenic hyperventilation

Answer 732

A

A. Middle cerebellar peduncle
B. Inferior cerebellar peduncle
C. Nodulus
D. Flocculus
E. None of the above

Answer 733

A

A. Middle cerebellar peduncle
B. Inferior cerebellar peduncle
C. Nodulus
D. Flocculus
E. None of the above

Answer 734

A

A. It connects the basilar artery between the superior cerebellar and the anterior inferior cerebellar arteries by passing through the petrous bone.
B. It connects the basilar artery by passing through the internal auditory
meatus.
C. It is present in 0.1% of the population.
D. There is increased frequency of arteriovenous malformations.
E. It is the second most common persistent fetal circulation.

Answer 735

A

A. 75%
B. 50%
C. 25%
D. 2%
E. 0.3%

The overall rate of HIV transmission from a single percutaneous exposure to HIV-infected blood with high viral load is of the order of 0.3%. Postexposure prophylaxis (PEP) has been shown in one study to reduce this rate by 80%. It is important to check viral loads of patients prior to elective surgery to keep operating room staff and surgeons safe.

Answer 736

A

A. 75%
B. 50%
C. 25%
D. 2%
E. 0.3%

Epidemiological studies of health care workers exposed to hepatitis C virus
through a needlestick or other percutaneous injury have found that the incidence of infection averages 1.8% per injury.

Answer 737

A

A. 75%
B. 50%
C. 25%
D. 2%
E. 0.3%

The risk of acquiring hepatitis B from a needlestick when the source was hepatitis B antigen-positive ranges from approximately 2 to 40%, depending
on the source’s level of viremia.

Answer 738

A

A. tentorial subdural hemorrhage.
B. subarachnoid hemorrhage.
C. normal CT scan.
D. dural sinus thrombosis.
E. arteriovenous fi stula

Answer 739

A

A. There is an autosomal recessive inheritance pattern.
B. In 20% of cases there is no hyperthermia accompanying the muscle rigidity.
C. It may be associated with autonomic instability.
D. It may be caused by muscle relaxants.
E. A mutation in the ryanodine receptor is related to malignant hyperthermia (MH).

Malignant hyperthermia has an autosomal dominant inheritance pattern. It may be caused by halothane or succinylcholine. Body temperature increase is about 1°C every 5 minutes. It is treated with dantrolene and discontinuation of the anesthetic

Answer 740

A

A. Cerebral aneurysm
B. Arteriovenous malformation
C. Endocrinopathy
D. Venous angioma
E. Progressive supranuclear palsy

The scan shows a cavernous angioma occurring at the thalamocaudate recess. These lesions may be associated with venous angioma

Answer 741

A

A. Type 1 Modic changes
B. Type 2 Modic changes
C. Yellow marrow replacement
D. Hypovascularization of the end plates
E. None of the above

Type 1 Modic changes show decreased intensity on T1-weighted images and increased intensity on T2-weighted images. Type 2 Modic changes show increased intensity on T1-weighted images and isointense signal intensity on T2-weighted images. Histopathology on type 1 changes demonstrates disruption and fi ssuring of the end plates and vascularized fi brous tissue. On type 2 changes, yellow marrow replacement is seen. Type 1 changes may convert to type 2 after a few years. There appears to be a spectrum of vertebral body marrow changes associated with degenerative disk disease.

Answer 742

A

A. Ataxia
B. Ipsilateral hearing defi cits
C. Contralateral temperature sensation loss
D. Lateral rectus palsy
E. Balance problems

The lesion represents a syrinx at the level of the inferior cerebellar peduncle.
The abducens nerve arises at a higher level and is less likely to be aff ected.
The anterolateral system courses ventral to the lesion and may be aff ected.
The vestibulocochlear nucleus is also located at this level

Answer 743

A

A. Ketamine
B. Thiopental
C. Halothane
D. Enflurane
E. Isoflurane

Ketamine raises systemic arterial blood pressure but not necessarily the perfusion in hypovolemic states. In hypotensive states of short duration from
endotoxin treatment, it improved the hemodynamics by augmenting the perfusion and the systemic pressure

Answer 744

A

A. Froin’s syndrome
B. Positive Queckenstedt’s sign
C. Male predominance with peak age in mid-40s
D. Cellular type
E. Neoplastic disease

The scans show a typical intramedullary ependymoma with blockage of CSF
fl ow, which is associated with Froin’s syndrome (clotting and xanthochromia in the CSF) and Queckenstedt’s sign, which is failure of jugular vein compression to increase CSF. The cervical type of intramedullary ependymoma is usually of the cellular type, more frequent in females in the mid-40s

Answer 745

A

A. Syringobulbia
B. Elevated serum angiotensin-converting enzyme
C. Aqueductal stenosis
D. Hallervorden–Spatz disease
E. Subdural hematoma

The MRI set demonstrates basilar meningitis with a trapped fourth ventricle and foramina of Luschka which occurs in sarcoidosis. Elevated angiotensin-converting enzyme levels is also a feature of this disease.

Answer 746

A

A. Proximal renal tubular function
B. Distal renal tubular function
C. Kidney glomerular function
D. None of the above

Answer 747

A

A. Proximal renal tubular function
B. Distal renal tubular function
C. Kidney glomerular function
D. None of the above

Answer 748

A

A. Proximal renal tubular function
B. Distal renal tubular function
C. Kidney glomerular function
D. None of the above

Answer 749

A

A. Proximal renal tubular function
B. Distal renal tubular function
C. Kidney glomerular function
D. None of the above

The proximal tubule plays a role in secreting organic acids and reabsorbing Na+
, water, glucose, bicarbonate, amino acids, and phosphate. The distal tubule’s role involves secretion of H+ and K+ and reabsorption of Na+
and Cl. The glomerular fi ltration rate is at its peak in young adulthood, at about 120 mL/min

Answer 750

A

A. The most signifi cant factor associated with recurrence is extent of resection.
B. A factor associated with recurrence is histology.
C. MIB-1 LI >7% is associated with a low likelihood of recurrence.
D. Malignant transformation to carcinoma frequently occurs.
E. Recurrence is dependent on the presence of intracytoplasmic inclusions.

The images show craniopharyngioma. The most signifi cant factor associated
with recurrence is extent of resection. Histology type is not correlated with
frequency of recurrence. MIB-1 LI > 7% is associated with a higher likelihood
of recurrence. Malignant transformation to carcinoma exceptionally occurs.

Answer 751

A

A. Central neurocytoma
B. Oligodendroglioma
C. Ependymoma
D. Endodermal sinus tumor
E. Yolk sac tumor

Central neurocytoma appears like oligodendroglioma histologically but is
positive for synaptophysin on immunohistochemistry.

Answer 752

A

A. Operculum
B. Sylvian fi ssure
C. Precentral sulcus
D. Rolandic fi ssure
E. None of the above

The parietal operculum is caudal to the inferior frontal gyrus. Directly inferior to the inferior frontal gyrus is the sylvian fissure

Answer 753

A

A. Nitroglycerine binds the surface of endothelial cells.
B. Nitroglycerine undergoes two chemical reductions to form nitric oxide.
C. Nitric oxide promotes the formation of cyclic guanosine triphosphate.
D. Nitric oxide moves out of the endothelial cell into adjacent smooth muscle
cell.
E. Nitric oxide increases cAMP in smooth muscle cells

Answer 754

A

A. 1% per year
B. 2% per year
C. 4% per year
D. 13% per year
E. 26% per year

Answer 755

A

A. 1% per year
B. 2% per year
C. 4% per year
D. 13% per year
E. 26% per year

Answer 756

A

A. 1% per year
B. 2% per year
C. 4% per year
D. 13% per year
E. 26% per year

Answer 757

A

A. Amphotericin
B. Angiotensin-converting enzyme inhibitors
C. Aspirin
D. Cyclosporin
E. Heparin

Answer 758

A

A. 2 hours
B. 2 days
C. 12 days
D. 22 days
E. 32 days

Intracellular methemoglobin appears as hyperintense on T1 and hypointense
on T2, and is usually present from 3 days to 2 weeks after a hemorrhage. Extracellular methemoglobin appears after 2 weeks and is hyperintense on T1 and T2. The images show hyperintensity on T1 and iso- to hypointensity on
T2, consistent with intracellular methemoglobin toward the end of 2 weeks following the hemorrhage.

Answer 759

A

A. Ethanol
B. Acetone
C. Methanol
D. Ethylene glycol (antifreeze)
E. Acethaldehyde

Answer 760

A

A. Ethanol
B. Acetone
C. Methanol
D. Ethylene glycol (antifreeze)
E. Acethaldehyde

Ethanol has a molecular weight of 46 and is lethal at levels > 350 mg/dL (least lethal). Methanol has the lowest molecular weight (32) and is the least lethal out of the three remaining substances (80 mg/dL needed for lethality). Ethylene glycol has the highest molecular weight (61) and is the most lethal (only 21 mg/dL needed to cause death)

Answer 761

A

A. whole blood.
B. fi brinogen.
C. platelets.
D. packed red blood cells.
E. cryoprecipitate

Answer 762

A

A. Ipsilateral Horner’s syndrome
B. Downbeat nystagmus
C. Loss of abdominal cutaneous refl ex
D. Neurogenic bladder
E. Extremity weakness

The scan shows a foramen magnum tumor. All the stated clinical fi ndings are
associated with this tumor location; however, neurogenic bladder tends to
occur very late

Answer 763

A

A. Saddle bilateral sensory defi cit
B. Symmetric motor loss
C. Loss of ankle jerk
D. Autonomic symptoms that occur late
E. Urinary retention and atonic anal sphincter that cause overfl ow urinary
incontinence and fecal incontinence

Answer 764

A

A. Sensory dissociation
B. Asymmetric motor loss
C. Late autonomic symptoms
D. Absence of ankle jerk and knee jerk
E. Numbness that tends to be more localized to saddle area

There is no sensory dissociation. Red fl ags for cauda equina syndrome are
erection diffi culty, extreme back pain, and groin numbness. An MRI scan taken in a lying down position may not display the stenosis so a standing MRI
scan, if available, is necessary. These patients should be sent to an emergency
room at once for stat MRI. In the setting of groin numbness only with back
pain, urodynamics and Foley catheter may not be absolutely necessary. One
should not delay care of these patients to the point in time where urodynamics become necessary. If these patients present in the emergency room,
they should not be sent home to follow up electively, they should be decompressed and stabilized on that hospital admission

Answer 765

A

A. Brachiocephalic artery
B. Right subclavian artery
C. Left subclavian artery
D. Right carotid artery
E. Left carotid artery

The aorta gives off , from proximal to distal, the brachiocephalic trunk, left
common carotid, and left subclavian arteries

Answer 766

A

A. Convergence defi cit
B. Adduction defi cit
C. Horizontal gaze palsy
D. Vertical gaze palsy
E. Parinaud’s syndrome

With bilateral internuclear ophthalmoplegia there is an adduction defi cit
in both eyes. This is observed in bilateral lesions of the medial longitudinal
fasciculus.

Answer 767

A

A. Acetylcholine
B. Noradrenaline
C. Dopamine
D. GABA
E. Glutamate

Answer 768

A

A. Acetylcholine
B. Noradrenaline
C. Dopamine
D. GABA
E. Glutamate

Answer 769

A

A. Acetylcholine
B. Noradrenaline
C. Dopamine
D. GABA
E. Glutamate

Answer 770

A

A. 1, 2, and 3 are true.
B. 1 and 3 are true.
C. 2 and 4 are true.
D. Only 4 is true.
E. All of the above are true.

Answer 771

A

A. Regional hypotension
B. CBF below critical level
C. Atrial fi brillation
D. Cardiac arrest
E. Anaphylaxis

Answer 772

A

A. Bernasconi’s artery
B. Persistent stapedial artery
C. Heubner’s artery
D. McConnell’s artery
E. Vidian artery

Answer 773

A

A. Thirty to fi fty percent of patients are febrile.
B. Spontaneous fusion of vertebral bodies may occur.
C. Haemophilus infl uenzae may be a causative organism in juvenile cases.
D. Radionuclide scans have a relatively low sensitivity.
E. There is increased incidence with intravenous drug abuse.

Answer 774

A

A. Increased neuronal density
B. Increased metabolism
C. Increased excitatory neurotransmission
D. Necrosis
E. None of the above

N-acetylaspartate (NAA), found in neurons and axons, is used as a neuronal
marker. A reduction in the NAA signal refl ects neuronal loss or injury, as seen
in many brain pathologies including neurodegenerative diseases. NAA peaks
typically represent increased neuronal density. Moderately increased choline
peaks and reduced NAA signal intensities indicate low-grade gliomas; highgrade tumors are characterized by distinctly higher choline peaks and even lower NAA signals, and the presence of lipid signals indicates tissue necrosis

Answer 775

A

A. Mucor
B. Aspergillus
C. Coccidioides
D. E. histolytica
E. Virus

Aspergillus has a predilection for the basal ganglia in some cases. It tends to invade blood vessels, cause hemorrhagic infarcts, and may cause formation of paranasal sinus mycetoma. Coccidioides can cause meningitis and caseating granulomas. The diagnosis of early cerebral infarction in a patient considered at risk for invasive aspergillosis, even without overt pulmonary disease, is an indication to institute aggressive antifungal therapy

Answer 776

A

A. Perivascular invasion
B. Hemorrhagic infarcts
C. Paranasal sinus mycetoma
D. Caseating granulomas
E. Increased prevalence with the use of chemotherapy and corticosteroids

Answer 777

A

A. Intravenous antibiotics
B. Surgical resection
C. Systemic chemotherapy and whole-brain radiation
D. Ommaya reservoir placement and intrathecal chemotherapy
E. Ventriculoperitoneal shunt

The MRI scan demonstrates leptomeningeal gliomatosis associated with a
high-grade glioma in the left occipital area. The best therapeutic option, given the diff use nature of the disease is, initially, chemotherapy and radiation

Answer 778

A

A. Stapedius
B. Tensor veli palatini
C. Stylopharyngeus
D. Posterior belly of digastric
E. None of the above

Answer 779

A

A. A
B. B
C.C
D.D

Answer 780

A

A. A
B. B
C.C
D.D

Answer 781

A

A. A
B. B
C.C
D.D

Answer 782

A

A. A
B. B
C.C
D.D

Functional residual capacity (D) does not change during exercise and is usually 2.4L. It is the sum or residual volume (C) and expiratory reserve volume
(ERV), or the diff erence between vital capacity (B) and ERV. Vital capacity
(VC) is usually around 4.4 to 5 L and is measured by having the patient inhale profoundly and exhale fully into a spirometer. Residual volume cannot
be measured directly and needs to be calculated as a percentage of exhaled
versus inhaled 10% helium-containing solution

Answer 783

A

A. Elevated N-acetylaspartate (NAA) peak and normal choline (Chol) and creatine (Cr) peaks
B. Elevated Cr peak and decreased Chol and NAA peaks
C. Increased Chol:Cr ratio and decreased NAA peak
D. Increased Cr:Chol ratio and decreased NAA peak
E. All of the above

Answer 784

A

A. Increased astrocytic density at point 3 as compared with point 1
B. Presence of tumor cells at point 3
C. Presence of necrosis at point 3
D. Increased metabolism at point 3
E. All of the above

Point 3 on the MR spectroscopy represents an area of tumor (glioma), which
shows an elevated Chol:Cr ratio and a decreased NAA peak. Other changes
seen in tumors may be decreased Chol and elevated NAA

Answer 785

A

A. Oxygen delivery
B. Oxygen uptake
C. Oxygen extraction ratio
D. Oxygen content
E. None of the above

The formula represents oxygen uptake

Answer 786

A

A. Cc O2 − Ca O2 / Cv O2 − Ca O2
B. (Cc O2 − Cv O2)/(Cc O2 − Ca O2)
C. Cc O2 − Ca O2/Cc O2 − Cv O2
D. (Cc O2 − Ca O2)/(Cc O2 − Cv O2)
E. (Cc O2 − Ca O2)/(Cv O2 − Ca O2)

Answer 787

A

A. Q = Pπr4/8VL
B. Q = 8PL/Vπr4
C. Q = Vπr4/8PL
D. Q = 8Vπr4/PL
E. None of the above

Answer 788

A

A. immediately in the ER.
B. before a CT scan.
C. in the operating room.
D. before antibiotics are given.
E. after the patient has been stabilized

If the pencil is pulled from his eye, there should be adequate measures to
stop bleeding and irrigate the wound. This can be properly performed only
in the operating room. This patient should be managed with antiepileptic
medication, broad-spectrum antibiotics, CT scan, immediate open surgical
debridement, and follow-up MRI in about a week

Answer 789

A

A. Single-level anterior cervical diskectomy and fusion (ACDF)
B. Two-level ACDF
C. Posterior decompression
D. Cervical corpectomy and fusion
E. Three-level ACDF

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