Adult Neurosurgery

Question 1

Which tumor is associated with hydrocephalus
and sudden death?
A. Colloid cyst
B. Glioblastoma multiforme
C. Lymphoma
D. Pilocytic astrocytoma

Answer 1

A. Colloid cyst

Colloid cysts represent 0.5 to 2% of all brain tumors and occur in the anterior part of the third ventricle near the foramen of Monro. These lesions can be associated with the development of hydro- cephalus and rapid clinical deterioration. Sudden death has been reported but is rare, and likely involves the colloid cyst acting as a ball valve and suddenly shifting and occluding cerebrospinal fluid outflow.

Question 2

Complex regional pain syndrome type 2 (formerly known as causalgia) is defined by what symptoms?
A. Burning pain, autonomic dysfunction, and tro-phic changes following obvious nerve damage
B. Increased perspiration in excess of what is re-
quired for regulation of body temperature
C. Burning pain, autonomic dysfunction, and tro-
phic changes without obvious nerve damage
D. An initial lack of sensation and tingling on one
side of the body followed later by severe,
chronic dysesthesias or allodynia
E. Recurrent hospitalizations with dramatic, un-
true, and extremely improbable tales of past
experiences

Answer 2

A. Burning pain, autonomic dysfunction, and tro-phic changes following obvious nerve damage

Complex regional pain syndrome (CRPS) type 2 follows nerve injury and originally was described following high-velocity missile injuries. CRPS type 1 (also known as reflex sympathetic dystrophy) is similar to CRPS type 2 in symptoms but does not demonstrate obvious nerve damage. (B) Increased perspiration in excess of what is required for regu- lation of body temperature suggests hyperhidro- sis. (C) CRPS type 2 requires nerve damage for the diagnosis. (D) Dejerine-Roussy syndrome follows a thalamic stroke and is characterized by an initial lack of sensation and tingling on one side of the body followed later by severe, chronic dysesthesias or allodynia. (E) Munchausen syndrome is charac- terized by recurrent hospitalizations with dramatic, untrue, and extremely improbable tales of past experiences.

Question 3

What factors contribute to the intracranial hemor-
rhage (ICH) score for a patient with a hemorrhagic
stroke?
A. Patient age, Glasgow Coma Scale (GCS) score,
acuity of ICH
B. ICH volume, GCS score, acuity of ICH
C. Intraventricular hemorrhage (IVH), position of ICH, patient age
D. Position of ICH, patient age, baseline Karnofsky
Scale score
E. Patient age, IVH, hemiplegia

Answer 3

C. Intraventricular hemorrhage (IVH), position of ICH, patient age

The intracranial hemorrhage (ICH) score is cal- culated from four factors: Glasgow Coma Scale (GCS) score, ICH volume, whether or not the ICH is infratentorial, and patient age. A GCS score of 3–4 yields two points, 5–12 yields one point, and 13–15 yields no points. One point is given to an ICH at least 30 cm3 in size, and an additional point is given to an ICH with an infratentorial origin. Finally, one point is given if the patient is at least 80 years old. The ICH score thus ranges from 0 to 6.

Question 4

A patient with a history of intravenous drug use is
seen in clinic with new-onset severe back pain. An
MRI is obtained that demonstrates bony erosion
and collapse of the L2/L3 disk. What is the next
step in the management of this patient?
A. Perform a lumbar puncture, and send spinal
fluid cultures.
B. Obtain a CT scan of the spine.
C. Obtain blood cultures.
D. Obtain a bone scan.
E. Schedule follow-up with a repeat MRI in 4 to 6
weeks.

Answer 4

C. Obtain blood cultures.

The likely diagnosis is diskitis, and the next step is to obtain blood cultures to confirm the hematogenous source and obtain an organism to treat. If blood cultures are negative, guided needle biopsy of the disk space should be done. Obtaining a serum erythrocyte sedimentation rate and C-reactive protein concentration also can be helpful. (A) A lumbar puncture is contraindicated due to the possibility of seeding the intrathecal space with an infectious agent.

Question 5

How is mechanical back pain associated with
activity?
A. Improves with activity
B. Worsens with activity
C. Relieved by standing
D. Worsens with axial unloading

Answer 5

A. Improves with activity

Although some patients with severe back pain and muscle spasms may improve with no more than 48 hours of bed rest, patients with mild to moderate back pain should return to near-normal work schedules and have improvement in back pain with activity, as this increases flexibility.

Question 6

Where should the dissection take place during a
transpsoas approach to the lumbar spine in order
to minimize the risk of nerve injury?
A. Anterior to the psoas major
B. Posterior to the psoas major
C. Through the bulk of the psoas major
D. Along the medial aspect of the psoas major
E. Along the lateral aspect of the psoas major

Answer 6

C. Through the bulk of the psoas major

The transpsoas approach to the lumbar spine places the entire lumbosacral plexus at risk for injury. The risk can be minimized by staying in the bulk of the psoas major muscle and with close neuromonitoring.

Question 7

A 17-year-old girl presents to the neuro-ophthal-
mology clinic with complaints of episodic diplopia
that has been present for the past week. The epi-
sodes occur about every hour and last around 1
minute each time. The patient has a history of a
transsphenoidal resection of a craniopharyngioma
3 years ago followed by radiation. Postoperative
ophthalmologic exams including visual fields have
been unremarkable. An MRI from 1 month ago
demonstrated no evidence of recurrent disease.
The patient is examined during one of these epi-
sodes and is found to have an exotropia of her right
eye that resolves spontaneously. She is prescribed
carbamazepine, and her symptoms improve. What
is her most likely diagnosis?
A. Craniopharyngioma recurrence
B. Myasthenia gravis
C. Ocular neuromyotonia
D. Seizures

Answer 7

C. Ocular neuromyotonia

Although rare, ocular neuromyotonia can occur after skull base radiation, with a reported mean time of 3.5 years following radiation. It is char- acterized by episodic, tonic contractions of one or more extraocular muscles, resulting in episodic diplopia. Varying success has been reported with membrane stabilizing agents (antiepileptics) or strabismus surgery.

Question 8

A man presents to clinic with results from an elec-
tromyographic (EMG) study showing fibrillations
and reduced motor unit potentials in his gluteus
medius and extensor digitorum longus. He has no
abnormal EMG findings in his biceps femoris (short
head). Weakness of foot eversion and numbness
on the dorsum of the foot are noted on his exam.
What nerve(s) is/are being affected?
A. L4 nerve root only
B. L5 nerve root only
C. S1 nerve root only
D. Common peroneal nerve proximal to the fibu-
lar head only
E. L5 nerve root and common peroneal nerve at
the fibular head

Answer 8

E. L5 nerve root and common peroneal nerve at
the fibular head

This patient has an injury to the L5 nerve root and the common peroneal nerve as explained. The peroneal nerve must be affected after it has given off its motor innervation to the short head of the biceps femoris, as this muscle is unaffected. The common peroneal nerve is most commonly injured as it crosses the fibular head, resulting in the symp- toms seen in this clinical scenario. The fibrilla- tions present on electromyography can indicate an axonal injury and uncontrolled and spontaneous firing of muscle cells. Present but reduced motor unit potentials indicate reduced motor unit recruit- ment and can indicate impeded nerve conduction. (A) With an L4 nerve root abnormality, abnormal- ities of the tibialis anterior would be expected. (B) An L5 nerve root abnormality explains the abnormalities in the extensor digitorum longus and gluteus medius but fails to address the abnormalities seen in the common peroneal nerve. Abnormalities in the gluteus minimus also would be seen with an L5 nerve root abnormality. (C) The S1 nerve root innervates the peroneus longus and brevis. (D) The common peroneal nerve supplies the short head of the biceps femoris before pass- ing around the fibular head and branching into a superficial and deep branch. The superficial branch supplies motor innervations to the muscles of the lateral compartment of the leg (the peroneus lon- gus and brevis, which evert the foot) along with sensory innervation to the lateral leg. The deep branch supplies motor innervation to the muscles of the anterior compartment of the leg (the tibialis anterior, extensor hallucis longus, extensor digi- torum longus, and peroneus tertius) along with muscles in the foot. It supplies sensory innervation to the dorsum of the foot in the first web space.

Question 9

A malignant peripheral nerve sheath tumor is dis-
covered in a patient’s left upper extremity. Where
should screening first be focused to detect distant
metastases?
A. Brain
B. Other extremities
C. Axial skeleton
D. Lungs
E. Lymph nodes

Answer 9

D. Lungs

When malignant peripheral nerve sheath tumors (MPNSTs) are discovered, a chest CT (fine cut) should be ordered to look for metastatic disease, as this is the most common location of metastatic spread. (E) Metastases of MPNSTs rarely occur in locations like the lymph nodes or the heart.

Question 10

What type of spinal arteriovenous malformation
typically is associated with low blood flow?
A. Dural
B. Juvenile
C. Extramedullary/intradural
D. Glomus

Answer 10

A. Dural

The American/English/French arteriovenous mal- formation (AVM) classification divides spinal vas- cular malformations into four types. Type 1 (dural AVM) is the most common; a radicular artery feeds into an engorged spinal vein along the posterior cord. This type is low flow. Type 2 (spinal glomus AVM) is a true AVM of the spinal cord. Type 3 (juvenile spinal AVM) is an enlarged glomus AVM that occupies the entire cross section of the cord and invades the vertebral body. This type may cause scoliosis. Type 4 (perimedullary AVM) forms a direct fistula between arteries supplying the spinal cord and draining veins. (C) Extramedullary/ intradural is not an AVM type and instead refers to an anatomic location typically used when describ- ing spinal neoplasms.

Question 11

Multiple sclerosis is a contraindication to what
procedural treatment for trigeminal neuralgia?
A. Microvascular decompression
B. Percutaneous radiofrequency rhizotomy
C. Percutaneous glycerol injection into the Meckel
cave
D. Percutaneous balloon microcompression
E. Stereotactic radiosurgery

Answer 11

A. Microvascular decompression

Although multiple sclerosis patients have a poorer response than patients without the disease to any treatment for trigeminal neuralgia, patients with multiple sclerosis respond very poorly to micro- vascular decompression.

Question 12

What is the major complication of a stereotactic
mesencephalotomy for medically intractable right
upper extremity pain?
A. Ipsilateral weakness
B. Anesthesia dolorosa
C. Memory deficits
D. Diplopia
E. Hypothalamic dysfunction

Answer 12

D. Diplopia

Diplopia can occur following a stereotactic mes- encephalotomy secondary to lesioning near the inferior colliculus. The diplopia is due to a defect in vertical eye movements and often resolves. (A) No motor tracts are encountered during a stereotactic mesencephalotomy. Weakness in the extremities is more likely to occur during a cordotomy.

Question 13

A patient undergoing a craniotomy for resection of
a vestibular schwannoma has a reasonable chance
of losing serviceable hearing following surgery if
the preoperative speech discrimination is below
what percentage?
A. 50%
B. 65%
C. 75%
D. 85%
E. 95%

Answer 13

C. 75%

Although the definition of serviceable hearing varies, most sources require a speech discrimina- tion score of at least 50 to 70%. For preoperative counseling, a speech discrimination score under 75% significantly raises the risk of not having ser- viceable hearing following a vestibular schwan- noma resection.

Question 14

A woman with a known pituitary macroadenoma
presents to the emergency room with a sudden,
intense headache and a new-onset ophthalmo-
plegia with her chronic visual field cuts. She en-
dorses photophobia. After imaging confirms the
most likely diagnosis, what is the next step in her
management?
A. Sumatriptan administration
B. Follow-up with repeat imaging in 6 weeks
C. Repeat pituitary lab work as an outpatient
D. Observation
E. Preparation for transsphenoidal decompres-
sion immediately

Answer 14

E. Preparation for transsphenoidal decompres-
sion immediately

The patient displays symptoms of pituitary apoplexy caused by a rapid expansion of her known pituitary adenoma secondary to necrosis or hemorrhage. This can lead to headache, nausea, somnolence, and other neurologic changes due to elevations in intracranial pressure along with exacerbated visual field cuts and ophthalmoplegia due to local mass effect. Treatment is emergent decompression of the sella turcica and pituitary lesion. Immediate administration of a stress dose of steroids also is important. Subarachnoid hemor- rhage can be seen with pituitary apoplexy, and an angiogram can be useful to rule out an aneurysm as a cause. (A) The patient likely is not having a migraine due to the new ophthalmoplegia with a known pituitary tumor. (B, D) This patient needs treatment soon to avoid permanent ophthalmic injury and neurologic damage associated with ele- vated intracranial pressures. (C) Lab work is unlikely to aid in the treatment of this patient as the pitu- itary lesion is unlikely to have grown suddenly. Outpatient lab work and waiting for inpatient labs to return will not affect the need for definitive treatment.

Question 15

A woman is referred to you for treatment of a cere-
bellopontine angle tumor. She has obvious weak-
ness of the right side of her face. She does have
some motion but has no motor contraction over
her forehead, she cannot close her eye completely,
and she has noticeable asymmetry of her mouth
when attempting to smile. What is her House-
Brackmann classification grade?
A. 2
B. 3
C. 4
D. 5
E. 6

Answer 15

C. 4

House-Brackmann facial nerve function classifi- cation grading ranges from 1 (normal) to 6 (total paralysis). Grade 2 is mild dysfunction. Grade 3 is obvious but not disfiguring facial asymmetry. Grade 4 dysfunction entails the inability to close the eye. Grade 5 is barely perceptible motion.

Question 16

What form of nicotine potentially will not decrease
spinal fusion rates?
A. Cigarette smoking
B. Chewing tobacco
C. Nicotine gum
D. Nicotine patches
E. No form of nicotine avoids the risk of de-creased spinal fusion rates

Answer 16

E. No form of nicotine avoids the risk of de-creased spinal fusion rates

Nicotine in all its forms has been shown to affect adversely spinal fusion rates

Question 17

What is the recommended torque used on a halo
pin on an adult skull?
A. 4 in-lbs
B. 8 in-lbs
C. 12 in-lbs
D. 20 in-lbs
E. 30 in-lbs

Answer 17

B. 8 in-lbs

(E) The recommended torque for the screws on many halo vests is 30 in-lbs.

Question 18

Injury to the subthalamic nucleus during a func-
tional lesioning procedure classically produces
what type of movement disorder?
A. Myoclonus
B. Hemiballism
C. Pill-rolling tremor
D. Fixed posture of limbs
E. Chorea

Answer 18

B. Hemiballism

Hemiballism is a unilateral, involuntary jerking of the proximal limb due to a lesion of the suthalamic nucleus. (A) Myoclonus describes shock-like con- tractions that are irregular and asymmetric and can have numerous etiologies. (C) A pill-rolling tremor is characteristic of parkinsonism and pathology involving the substantia nigra pars compacta. (D) Dystonias leading to fixed limb postures may be due to putaminal destruction. (E) Chorea is seen in Huntington disease and is a result of striatum atrophy.

Question 19

Deep brain stimulation in the setting of Parkinson
disease is expected to result in brief minimal im-
provement to what characteristic of the disease?
A. Dyskinesia
B. Balance
C. Tremors
D. Rigidity
E. Cognitive impairment

Answer 19

B. Balance

Patients with Parkinson disease who have under- gone deep brain stimulation surgery experience a brief period of improvement in balance followed by a return of balance difficulties. The procedure is more effective at reliving symptoms of dyskinesia, tremors, and rigidity.

Question 20

What electromyography/nerve conduction study
finding supports a diagnosis of lumbar radiculo-
pathy from a herniated disk?
A. Paraspinal muscle fibrillations
B. Abnormal sensory nerve action potentials
(SNAPs)
C. Increased motor fiber recruitment with voli-
tional activity
D. Absence of spontaneous sensory nerve activity

Answer 20

A. Paraspinal muscle fibrillations

Electromyography is not sensitive for radiculop- athy; however, when it is abnormal, it is very spe- cific. Paraspinal muscles are innervated by dorsal rami, which exit proximally to the dorsal root gan- glion. Paraspinal muscle fibrillations can indicate irritation of these dorsal rami. (B) Sensory nerve action potentials (SNAPs) are normal in lesions proximal to the dorsal root ganglia; therefore, most disk herniations do not affect SNAPs. (C) Increased motor fiber recruitment indicates a myopathic pro- cess. (D) Spontaneous nerve activity (including positive sharp waves and fibrillation potentials) can be seen after denervation.

Question 21

A patient presents with a blunt cerebrovascular
injury after a motor vehicle collision. The patient
has no intracranial hemorrhage. CT angiogram
reveals an internal carotid artery luminal irregu-
larity with < 25% stenosis. What is the next step in
the management of this patient?
A. No acute intervention; repeat imaging in 4 to
6 weeks.
B. Initiate a heparin drip if there are no contraindications.
C. Perform endovascular stenting.
D. Perform a ligation/occlusion of carotid artery.
E. Initiate antiplatelet therapy if there are no
contraindications.

Answer 21

B. Initiate a heparin drip if there are no contraindications.

Blunt cerebrovascular injuries of the internal carotid artery are common following motor vehi- cle collisions and are thought to be related to neck hyperextension with lateral rotation. The injuries most often occur 2 cm from the origin of the inter- nal carotid artery. The blunt cerebrovascular injury (BCVI) classification is as follows: grade 1, luminal irregularity with ≤ 25% stenosis; grade 2, luminal irregularity with > 25% stenosis or an intralumi- nal thrombus/raised intimal flap; grade 3, pseudo- aneurysm; grade 4, complete occlusion; grade 5, transection with extravasation. The incidence of stroke increases with the grade. Although outcomes are not entirely known, the data suggest that anti- coagulation may reduce the risk of injury progres- sion with grade 1 injuries.

Question 22

Halo bracing is least effective for what type of cer-
vical fractures?
A. Odontoid fractures
B. Levine type 2 pars fractures
C. Midcervical spine fractures
D. C1 fractures with a type 3 odontoid fracture
E. Teardrop fractures

Answer 22

C. Midcervical spine fractures

Because of “snaking,” which may occur between the halo fixation points and the vest, a halo brace is best suited for upper and lower cervical spinal fractures but is poor at maintaining distraction.

Question 23

For nonemergent neurosurgical procedures, it is
recommended that a patient’s INR be less than or
equal to what value?
A. Posterior inferior cerebellar artery
B. Anterior inferior cerebellar artery
C. Superior cerebellar artery
D. Posterior cerebellar artery
E. Vertebral artery

Answer 23

B. Anterior inferior cerebellar artery

The anterior inferior cerebellar artery can com- press cranial nerve VII to produce hemifacial spasm. (A) The posterior inferior cerebellar artery is asso- ciated with glossopharyngeal neuralgia. (C) The superior cerebellar artery is associated with tri- geminal neuralgia.

Question 24

For nonemergent neurosurgical procedures, it is recommended that a patient’s INR be less than or equal to what value?
A. 1.0
B. 1.2
C. 1.4
D. 1.6

Answer 24

C. 1.4

In clinical studies, an INR of 1.4 is considered safe for performing a percutaneous needle liver biopsy. Extrapolated from this, an INR of 1.4 is considered safe for performing neurosurgical pro- cedures. The prothrombin time should be 13.5 sec- onds or less.

Question 25

With pituitary tumors, what optic chiasm position
is most associated with optic nerve compression?
A. Prefixed chiasm
B. Postfixed chiasm
C. Chiasm superior to the sella turcica
D. Neutral position chiasm

Answer 25

B. Postfixed chiasm

A pituitary tumor with a postfixed chiasm (located posterior to its normal position over the dorsum sellae) has an increased likelihood of com- pressing the optic nerves and causing a “pie in the sky” deficit (superotemporal quadrantanopsia) through compression of the knee of Wilbrand. Postfixed chiasms also can result in chiasmatic compression and a bitemporal hemianopsia. (A) A prefixed chiasm (located anterior to its normal position over the tuberculum sellae) is associated with optic tract compression and a homonymous hemianopsia. (C, D) The optic chiasm normally lies superior to the sella turcica.

Question 26

Over 95% of vestibular schwannomas present with
progressive unilateral or asymmetric sensorineu-
ral, high-frequency hearing loss. In general, what is
considered the definition of serviceable hearing?
A. Pure tone audiogram of 40 dB or less; speech
discrimination score of at least 40%
B. Pure tone audiogram of 60 dB or less; speech
discrimination score of at least 60%
C. Pure tone audiogram of 60 dB or less; speech
discrimination score of at least 40%
D. Pure tone audiogram of 40 dB or less; speech discrimination score of at least 60%
E. American Academy of Otolaryngology–Head
and Neck Surgery (AAO-HNS) class C or D

Answer 26

D. Pure tone audiogram of 40 dB or less; speech discrimination score of at least 60%

Hearing is considered serviceable if the pure tone audiogram is less than or equal to 50 dB and speech discrimination is 50% of more (the “50/50” rule). American Academy of Otolaryngology-Head and Neck Surgery classifications A (30/70) and B (50/50) are considered serviceable and preservable.

Question 27

A 50-year-old woman presents with an acute onset
of severe headache, bitemporal hemianopsia, and
cranial nerve III palsy. She is alert and conversant.
What is the most appropriate next step in this pa-
tient’s management?
A. Rapid administration of corticosteroids
B. Cerebral angiography
C. Administration of nimodipine
D. Obtaining an erythrocyte sedimentation rate,
C-reactive protein concentration, and blood
cultures
E. Intracranial pressure monitoring

Answer 27

A. Rapid administration of corticosteroids

Pituitary apoplexy can be considered a surgical emergency if it is rapidly progressive. In addition, given the compromise of the pituitary gland, prompt treatment with corticosteroids is neces- sary. (B, C) The rapid onset of a headache may suggest an aneurysmal subarachnoid hemorrhage aneurysm, and a posterior communicating artery aneurysm may produce a cranial nerve III palsy. Subarachnoid hemorrhage is not associated with bitemporal hemianopsia, however. (D) Cavernous- carotid fistulae often are associated with a pulsatile proptosis. Infectious etiologies (e.g., Tolosa-Hunt and Gradenigo syndromes) often include a painful ophthalmoplegia. (E) Increased intracranial pres- sure and uncal herniation could produce a cranial nerve III palsy, but bitemporal hemianopsia in an awake patient likely would not occur.

Question 28

A 19-year-old man presents following a motor
vehicle collision complaining of lower extremity
weakness. He is found to have a thoracic spine
Chance fracture. He has full strength in his upper
extremities. He has sensation in his lower extrem-
ities and perineum, and his motor strength in his
lower extremities ranges from 4–/5 to 4/5. What
is his American Spinal Injury Association (ASIA)
impairment scale score?
A. A
B. B
C. C
D. D
E. E

Answer 28

D. D

The American Spinal Injury Association (ASIA) impairment scale indicates the completeness of a spinal cord injury and is different from the ASIA motor scale. ASIA A represents a complete injury without motor or sensory function below the injury level. ASIA E represents normal motor and sensory function. ASIA B is an incomplete injury with preservation of sensory but not motor func- tion below the level of injury. ASIA C is an incom- plete injury with preservation of motor function in at least half of the key muscles below the level of injury graded at less than 3/5, whereas, in ASIA D, half of the key muscles below the level of injury have at least 3/5 strength. Of note, sensory preser- vation requires that the S4 and S5 segments also be intact. The ASIA impairment scale only applies to patients who have sustained spinal cord injuries and should not be used to describe a neurologic exam otherwise.

Question 29

What incomplete spinal cord injury syndrome is
associated with a poor prognosis for recovery and
dissociated sensory loss?
A. Central cord syndrome
B. Anterior cord syndrome
C. Brown-Séquard syndrome
D. Posterior cord syndrome
E. Cauda equina syndrome

Answer 29

B. Anterior cord syndrome

Anterior cord syndrome (anterior spinal artery syndrome) presents with paraplegia and dissoci- ated sensory loss, with loss of pain and tempera- ture sensation but with preservation of posterior column function (positional and fine touch sensa- tion). It can result from an infarct involving the anterior spinal artery. (A) Central cord syndrome presents with a greater motor deficit in the upper extremities relative to the lower extremities. It often results from a hyperextension injury in the presence of degenerative osteophytes. The over- all prognosis is that half of affected patients even- tually will be able to ambulate independently. (C) Brown-Séquard syndrome presents with disso- ciated sensory loss (loss of pain and temperature sensation with preserved light touch sensation), with ipsilateral paresis and posterior column dys- function. Of the listed syndromes, Brown-Séquard syndrome has the best prognosis, with 90% of affected patients regaining ambulatory status. (D) Posterior cord syndrome is rare. Symptoms include pain and paresthesias with minimal long tract findings. (E) Cauda equina syndrome is com- pressions of the cauda equina (not the spinal cord), resulting in urinary retention, saddle anesthesia, motor weakness, and low back pain due to the involvement of multiple nerve roots.

Question 30

When placing a C2 pedicle screw, what is the tra-
jectory of the screw?
A. Superior and medial
B. Superior and lateral
C. Inferior and medial
D. Inferior and lateral
E. Parallel to the spinous process

Answer 30

A. Superior and medial

The pars interarticularis and pedicle of the C2 vertebral body, from posterior to anterior, are ori- ented superiorly and medially. The entry point for C2 pedicle screw placement is 3 to 4 mm superior to the inferior margin of the C2 inferior facet and at the midpoint mediolaterally with a trajectory of 20 to 30 degrees medially and 25 degrees supe- riorly. The vertebral artery courses laterally as it passes through the C2 transverse foramen so that the more superior the screw is placed, the far- ther away from the vertebral artery the screw is located.

Question 31

What is a relative contraindication for the place-
ment of an anterior odontoid screw that may make
surgery technically very difficult?
A. Type 2 odontoid fracture
B. Combined 5-mm overhang of the lateral masses
of C1 on C2
C. Acute fracture
D. Reducible fracture
E. Barrel chest

Answer 31

E. Barrel chest

Relative contraindications for odontoid screw placement include a type 3 odontoid fracture, large fracture gaps, irreducible fractures, chronic fractures, pathological fractures, and fracture lines that are oblique to the frontal plane. Odontoid screws are useful for acute, type 2 fractures with intact ligaments but can be difficult to place in patients with short, thick necks or barrel chests. This relative contraindication sometimes can be circumvented with appropriate instrumentation. (B) The most significant absolute contraindication for odontoid screw placement is the disruption of the transverse atlantal ligament as seen on MRI or indirectly if the sum of the overhang of the lat- eral masses of C1 on C2 exceeds 7 mm. This latter assessment is known as the rule of Spence.

Question 32

A patient presents in the emergency room with a
cervical spine fracture and the following radio-
graphic findings: a triangular bone fragment frac-
tured off the anterior inferior vertebral body,
retrolisthesis of the caudal vertebrae, and disrup-
tion of the facet joints and the disk space. What
type of fracture is suspected?
A. Avulsion fracture
B. Clay-shoveler fracture
C. Jefferson fracture
D. Teardrop fracture
E. Locked facets

Answer 32

D. Teardrop fracture

Teardrop fractures are compression/flexion injuries that often are unstable. They usually pre- sent with chip fractures and retrolisthesis, sagittally oriented fractures, a kyphotic deformity, facet/disk space disruption, and soft tissue swelling. (A) Avul- sion fractures present with chip fractures as a result of anterior longitudinal ligament traction on the fractured bone (a hyperextension injury). There often is no misalignment, body fracture, or poste- rior element or disk disruption. (B) A clay-shoveler fracture is an avulsion of the C7 spinous process. (C) Jefferson fractures are four-point burst frac- tures of the C1 ring. They are classified as unstable but often are treated with orthosis; they typically present without neurologic deficits. (E) Locked facets result from distraction/flexion injuries and often present with anterolisthesis.

Question 33

A patient presents after a significant fall from a
ladder with an L2 burst fracture that has a 70% loss
of height, 50% canal stenosis due to retropulsion,
and 15 degrees of angulation. How would you re-
duce this fracture with ligamentotaxis?
A. Removing ligaments such as the ligamentum
flavum that would allow for easier manipula-
tion of the fracture
B. Distracting pedicle screws to reduce indirectly the retropulsed segment by putting tension on the posterior longitudinal ligament
C. Compressing pedicle screws to reduce the ret-
ropulsed fragment by releasing tension on the
posterior longitudinal ligament
D. Placing a strut or cage to reduce the loss of
height of the vertebral body
E. Positioning the patient to utilize the anterior
longitudinal ligament to reduce the kyphotic
angulation associated with the fracture

Answer 33

B. Distracting pedicle screws to reduce indirectly the retropulsed segment by putting tension on the posterior longitudinal ligament

Ligamentotaxis is the theory for the practice that is used by some physicians to “pull” bony frag- ments that are in the central canal back to their normal positions (assuming the posterior longitu- dinal ligament is intact). Typically, this technique is used with a distraction technique such as with pedicle screws. (A, C–E) These techniques are uti- lized in deformity and spinal trauma surgery but are not considered ligamentotaxis.

Question 34

In what zone is a sacral fracture that occurs in the
region of the sacral foramina?
A. Zone 1
B. Zone 2
C. Zone 3 (vertical)
D. Zone 4 (transverse)
E. Zone 5

Answer 34

B. Zone 2

Sacral zone 2 fractures occur vertically, ascend the sacral foramina, and may cause unilateral L5, S1, or S2 root injuries (including sciatica). (A) Sacral zone 1 fractures occur at the sacral ala and may be associated with an L5 root injury. (C) Sacral zone 3 fractures occur within the sacral canal and can cause sphincter dysfunction with bilateral nerve root injuries and saddle anesthesia. Fractures extending vertically in zone 3 are associated with pelvic ring fractures. (D) Transverse sacral frac- tures sometimes are classified as zone 4 injuries and occur from falls. They can produce severe neu- rologic deficits. (E) There is no zone 5.

Question 35

Fisher grade 3 is differentiated from Fisher grade 2
for aneurysmal subarachnoid hemorrhage by what
characteristic?
A. Greater than 1 mm of blood
B. Presence of hydrocephalus
C. Intracerebral or intraventricular clot
D. Presence of vasospasm
E. Greater than 1 cm of blood

Answer 35

A. Greater than 1 mm of blood

The Fisher grading system is effective in deter- mining the risk of vasospasm associated with an- eurysmal subarachnoid hemorrhage according to the amount of blood seen on CT. Grade 1 is without subarachnoid hemorrhage. Grade 2 indicates sub- arachnoid hemorrhage less than 1 mm in thick- ness. Grade 3 indicates a localized clot or layer of subarachnoid hemorrhage at least 1 mm in thick- ness. (C) Grade 4 indicates intraparenchymal or intraventricular hemorrhage.

Question 36

A 37-year-old man presents with a sudden onset
of the “worst headache of my life.” The CT shows
intraventricular hemorrhage that you suspect re-
sulted from hemorrhage entering through the lam-
ina terminalis. You are suspicious of an aneurysm
at what location?
A. Middle cerebral artery bifurcation
B. Posterior communicating artery
C. Internal carotid artery terminus
D. Anterior communicating artery
E. Basilar artery tip

Answer 36

D. Anterior communicating artery

Anterior communicating artery aneurysms often present with blood in the anterior interhemi- spheric fissure, a hematoma in the gyrus rectus, and intraventricular hemorrhage in the third ven- tricle, which is thought to reach the ventricles through the lamina terminalis.

Question 37

A patient presents with subacute bacterial endo-
carditis. Evaluation and workup includes a CT an-
giogram followed by a cerebral angiogram that
demonstrates two small aneurysms on distal left
middle cerebral artery branches. What treatment
modality is indicated?
A. Endovascular coiling
B. Surgical clipping
C. Antibiotics and serial imaging
D. Observation

Answer 37

C. Antibiotics and serial imaging

Mycotic aneurysms are common in bacterial endocarditis and occur in 3 to 15% of patients with this diagnosis. The aneurysms are found most commonly in the distal middle cerebral artery branches. At least 20% of patients have mul- tiple aneurysms, and there is an association with immunocompromised and intravenous drug abuse patients. Treatment consists of antibiotic therapy, as these aneurysms are friable and not easily amenable to surgical or endovascular treatments. Serial angiograms are used to follow the resolu- tion of mycotic aneurysms. Surgical clipping may be indicated in patients with subarachnoid hemor- rhage, increasing aneurysm size despite antibiotic treatment, failure of antibiotics to resolve the aneurysm, and focal deficits.

Question 38

Following the standard of care, what role does
brachytherapy play as an adjunctive treatment for
high-grade gliomas?
A. Brachytherapy is a viable alternative to whole
brain radiation.
B. Brachytherapy is superior to stereotactic
radiosurgery.
C. Brachytherapy has no role as an adjuvant to whole brain radiation.
D. Brachytherapy can be useful in addition to
whole brain radiation.
E. Brachytherapy can substitute for whole brain
radiation.

Answer 38

C. Brachytherapy has no role as an adjuvant to whole brain radiation.

Brachytherapy provides no significant overall
survival or quality-of-life benefits when compared
with whole brain radiation and should not be used
alone or as an adjuvant therapy for high-grade gliomas. This is due to the diffuse nature of gliomas
and the side effects of brachytherapy.

Question 39

Following resection of a low-grade oligodendrogli-
oma, what is the next step in adjuvant therapy?
A. Intravenous chemotherapy
B. Focused radiation
C. Whole brain radiation
D. Intrathecal chemotherapy

Answer 39

A. Intravenous chemotherapy

Following resection of a low-grade oligodendroglioma, chemotherapy is the mainstay of adjuvant
therapy, with radiation reserved for higher grade
lesions due to their aggressiveness and more diffuse characteristics. The typical chemotherapy protocol of procarbazine, CCNU, and vincristine is
given intravenously and not intrathecally.

Question 40

What is the complication rate for shunting a
patient with normal pressure hydrocephalus?
A. 5 to 10%
B. 10 to 25%
C. 25 to 40%
D. 40 to 55%

Answer 40

C. 25 to 40%

Complications rates are high when shunting
patients with normal pressure hydrocephalus, likely
in part due to the advanced average age of the
patients with the condition. Complications include
subdural hematomas, shunt infections, intracranial
hemorrhages, seizures, and shunt malfunctions.
As for the symptoms of normal pressure hydrocephalus, incontinence followed by gait abnormalities is the symptom most likely to improve with
shunting. Dementia is the symptom least likely to
improve.

Question 41

A woman is referred to your office for symptoms
consistent with carpal tunnel syndrome. She has
had a nerve conduction study showing that the
proximal median nerve latency is shorter than the
distal median nerve latency. What is the explana-
tion for this finding?
A. Poor quality/erroneous nerve conduction study
B. Lesion of the proximal median nerve
C. Presence of a Martin-Gruber anastomosis
D. Marinacci syndrome
E. Diabetic neuropathy

Answer 41

C. Presence of a Martin-Gruber anastomosis

A Martin-Gruber median to ulnar nerve anastomosis occurs in 15 to 30% of individuals and consists of a communicating nerve branch between
median and ulnar nerves. A clue to the presence of
a Martin-Gruber anastomosis with carpal tunnel
syndrome is a faster than expected conduction velocity in the median nerve in the forearm. In severe
carpal tunnel syndrome, because nerve fibers are
passing around the carpal ligament through the
ulnar nerve, antecubital fossa stimulation may
result in thenar stimulation faster than with stimulation at the wrist (there also will be a positive
deflection). (D) Marinacci syndrome is a “reverse”
Martin-Gruber anastomosis characterized by an
ulnar to median nerve anastomosis that can cause
carpal tunnel syndrome from an ulnar nerve compression at the elbow.

Question 42

A 17-year-old boy is brought to the emergency
room following a motor vehicle collision with mul-
tiple fatalities. He is alert, awake, and oriented. He
denies neck pain, has no midline tenderness, and
does not have any other injuries. The neurologic
exam is unremarkable. He has not used alcohol or
drugs. What is the minimum radiographic study
needed to clear the cervical spine?
A. Radiographs are not indicated
B. Upright lateral and AP X-rays
C. Flexion-extension X-rays
D. Lateral and AP X-rays with CT imaging of areas
that are suspicious or not easily seen on plain
films
E. Thin-cut axial CT scan from the occiput to T1
with sagittal and coronal reconstructions

Answer 42

A. Radiographs are not indicated

There are five NEXUS criteria to indicate the
need for cervical spine imaging: midline cervical
tenderness, focal neurologic deficits, altered level
of consciousness, intoxication, and painful distracting injuries. If these are all negative, radiographic
studies are not indicated. In trauma patients who
are symptomatic, obtunded, or have an unreliable
neurologic exam, a thin-cut axial CT scan is indicated with reconstructions.

Question 43

A 63-year-old diabetic man with a remote history
of vertebral osteomyelitis presents to the hospital
with low back pain and pain down the anterior
part of the thigh for the past 3 weeks. Neuro-
logic exam is unremarkable. MRI suggests a psoas
and epidural abscess without severe compres-
sion. What is the next appropriate step in this pa-
tient’s management?
A. Discharge home on oral antibiotics with
follow-up with an infectious disease specialist.
B. Admit to the floor, place on antibiotics, and
consult interventional radiology for culture
and biopsy of the epidural abscess.
C. Consult interventional radiology for culture
and biopsy of the epidural space prior to start-
ing antibiotics.
D. Admit to the floor, obtain blood cultures, and
consult interventional radiology for biopsy of
the psoas abscess prior to administering anti-
biotics (if the biopsy can be done in a timely manner).
E. Perform a decompressive laminectomy with
evacuation of the abscess.

Answer 43

D. Admit to the floor, obtain blood cultures, and
consult interventional radiology for biopsy of
the psoas abscess prior to administering anti-
biotics (if the biopsy can be done in a timely manner).

Medical management of patients with epidural
abscesses is preferred when there are long-standing
symptoms without progressive neurologic deficits,
when imaging is not worrisome for severe compression, in patients with prohibitive operative risk
factors, and in patients with complete paralysis for
longer than 3 days. Epidural biopsy is not recommended; however, disk space/vertebral body biopsy
is a reasonable option.

Question 44

An 82-year-old woman presents to the neurosur-
gery clinic with typical trigeminal neuralgia. She
has substantial medical comorbidities and would
like to avoid surgery. The patient opts for stereo-
tactic radiosurgery. What factor would predict a
favorable outcome?
A. Absence of atypical pain
B. Using a radiation dose less than 60 Gy
C. Prior successful surgical microvascular
decompression
D. Decreased sensation in the affected nerve
prior to treatment
E. Trigeminal neuralgia related to multiple
sclerosis

Answer 44

A. Absence of atypical pain

Absence of atypical pain is a favorable prognosticator in surgical and radiosurgical candidates for
trigeminal neuralgia treatment. Other favorable
factors include using higher radiation doses, a lack
of previous trigeminal neuralgia operations, and
normal pretreatment sensory function.

Question 45

What is the most effective surgical option for the
treatment of glossopharyngeal neuralgia in the
absence of vascular compression?
A. Cranial nerve IX rhizotomy alone
B. Cranial nerve X rhizotomy alone
C. Cranial nerve IX rhizotomy with sectioning the upper one third of cranial nerve X
D. Extracranial nerve ablation of cranial nerve IX
E. Cranial nerve XI rhizotomy alone

Answer 45

C. Cranial nerve IX rhizotomy with sectioning the upper one third of cranial nerve X

When an offending vessel (classically the posterior inferior cerebellar artery) is seen compressing
cranial nerve IX, microvascular decompression
(MVD) is the preferred treatment choice. During
an exploration that fails to reveal vascular compression of the nerve, the most effective treatment
includes sectioning of cranial nerve IX and the
upper rootlets of cranial nerve X. Studies suggested
that there is a higher rate of pain recurrence when
both nerves are not sectioned simultaneously. The
risks of sectioning cranial nerve X may include
significant bradycardia, dysphagia, and voice
hoarseness.

Question 46

A teenager suffering from a defect in his L5 pars
interarticularis as a result of an insufficiency frac-
ture of the pars can be characterized as having
what type of spondylolisthesis?
A. Dysplastic
B. Isthmic
C. Degenerative
D. Traumatic
E. Pathological

Answer 46

B. Isthmic

There are five types of spondylolisthesis: type 1,
dysplastic, is congenital and related to spina bifida;
type 2, isthmic (spondylolytic), is a result of pars
insufficiency fractures, an elongated pars from
repetitive fractures/healing, or acute fractures;
type 3, degenerative, usually occurs at L4/L5 without a break in the pars interarticularis; type 4,
traumatic, is due to a posterior element fracture
(other than the pars); type 5, pathological, is secondary to a tumor or bone disorder.

Question 47

You perform a stereotactic-guided biopsy of a tha-
lamic lesion. You notice bleeding from the cannula.
What is the next step?
A. Perform an emergent craniotomy and
exploration.
B. Immediately abort the procedure, and obtain
a CT.
C. Abort the procedure, wake the patient, and
obtain a neurologic exam.
D. Elevate the head of the bed, decrease the blood
pressure, and irrigate the cannula.
E. Insert a Fogarty catheter into the cannula,
inflate the balloon, and obtain a CT.

Answer 47

D. Elevate the head of the bed, decrease the blood
pressure, and irrigate the cannula.

The main complication related to a blind, stereotactic-guided biopsy is hemorrhage. Most bleeding
is capillary or venous, and can be managed by
conventional methods of cannula irrigation, head
elevation, and induced hypotension with a systolic
blood pressure around 90 mm Hg. Nevertheless,
craniotomy and clot evacuation may be necessary
to obtain hemostasis in refractory bleeding

Question 48

What is the most common location of mycotic
aneurysms?
A. Distal middle cerebral artery branches
B. Proximal anterior cerebral artery
C. Distal anterior cerebral artery
D. Basilar tip
E. Posterior inferior cerebellar artery

Answer 48

A. Distal middle cerebral artery branches

Mycotic aneurysms occur in distal middle cerebral artery branches 75 to 80% of the time. They
also occur in distal anterior cerebral artery branches
less often. Twenty percent of patients with mycotic
aneurysms have multiple aneurysms, and mycotic
aneurysms may occur in up to 15% of patients with
subacute bacterial endocarditis. The most common pathogen is Streptococcus viridans

Question 49

A 35-year-old woman presents with spontaneous
neck pain. A noncontrast head CT demonstrates
subarachnoid hemorrhage, and an angiogram
reveals a lesion suspicious for an intradural ver-
tebral artery dissection. What is the appropriate
treatment for this finding?
A. Observation if asymptomatic
B. Immediate heparinization followed by oral
anticoagulation
C. Immediate surgery or endovascular treatment
D. Delayed surgery to allow for swelling
resolution
E. Nonoperative treatment followed by a delayed
angiogram in 5 to 7 days to assess healing

Answer 49

C. Immediate surgery or endovascular treatment

Vertebral dissections can lead to pain, transient
ischemic attacks, strokes, and subarachnoid hemorrhage. Rebleeding is common and occurs in 30%
of those with subarachnoid hemorrhage. In dissections without hemorrhage or large ischemic strokes,
heparin followed by oral anticoagulation should
be started immediately. Surgery (hunterian ligation following a balloon test occlusion study), clipping with or without bypass, graft placement or
wrapping, and endovascular treatment (stents/
occlusion/angioplasty) are the treatments of choice
for patients presenting with subarachnoid hemorrhage, extradural lesions that progress, or symptoms that persist despite medical therapy.

Question 50

A 32-year-old man presents with slurred speech
and a hypoglossal palsy. He reported that he was
involved in a motor vehicle collision 3 weeks prior
for which he did not pursue medical evaluation. He
reports that he has had neck pain since the acci-
dent. What is the suspected diagnosis?
A. Atlanto-occipital dislocation
B. Vertebral artery dissection with stroke
C. Odontoid fracture
D. Clival fracture
E. Condyle fracture

Answer 50

E. Condyle fracture

Condyle fractures are not common but can present with delayed cranial nerve palsies, especially a
hypoglossal palsy due to the fact that the hypoglossal canals are intimate with the occipital condyles. Brainstem findings also occasionally occur.
Treatment is with a rigid collar unless the occipital
to C1 interval is more than 2 mm, at which point
surgical stabilization is required.

Question 51

A 43-year-old woman presents to the neurosur-
gery clinic complaining of hand clumsiness. A
neurologic exam reveals wasting and weakness of
the abductor pollicis brevis and hand intrinsics.
There is sensory loss over the medial forearm, but
sensation in the hand is normal. According to the
above findings, what is the next appropriate test
for diagnosis?
A. MRI of the brain
B. Cerebrospinal fluid studies
C. Chest radiograph
D. MRI of the cervical spine
E. Cervical spine radiographs with oblique and apical lordotic views

Answer 51

E. Cervical spine radiographs with oblique and apical lordotic views

Neurologic thoracic outlet syndrome is rare and
usually affects women. One cause is a constricting
band that originates from the first rib or an elongated C7 transverse process that causes compression of the C8 and T1 nerve roots, proximal trunk
of the brachial plexus, or median cord. Sensory
changes often spare the median nerve (which
passes through the upper and middle trunks of the
brachial plexus) but are seen in the lower trunk
(C8 and T1 nerve roots). Electromyography in thoracic outlet syndrome is unreliable but may have
positive findings if sensory nerve action potentials
are analyzed in the medial antebrachial cutaneous
nerve. (D) MRIs of the cervical spine are poor for
detecting bony abnormalities in thoracic outlet
syndrome but may rule out pathologies that mimic
thoracic outlet syndrome such as cervical disk
herniation.

Question 52

What tumor often arises from the “roof” of the
fourth ventricle?
A. Ependymoma
B. Juvenile pilocytic astrocytoma
C. Brainstem glioma
D. Choroid plexus papilloma
E. Medulloblastoma

Answer 52

E. Medulloblastoma

Medulloblastomas often arise from the cerebellar vermis close to the fastigium near the posterior
medullary velum (the roof of the fourth ventricle).
(A) Ependymomas often arise from the floor of the
fourth ventricle. (B) Juvenile pilocytic astrocytomas (JPAs) can occur in the optic/hypothalamic
areas, brainstem, cerebellum, and spinal cord. Cerebellar JPAs often are hemispheric. (C) Brainstem
gliomas can be diffuse, cervicomedullary, and focal
or dorsally exophytic. They do not arise from the
roof of the fourth ventricle. (D) Choroid plexus
papillomas commonly are found in the lateral ventricles and arise from the choroid plexus.

Question 53

A 38-year-old man presents with seizures, and
workup reveals an arteriovenous malformation
that is 6.4 cm in size, involves the posterior fronto-
parietal and occipital lobes, and drains into the
galenic system. What is the preferred treatment
option for this lesion?
A. Embolization alone
B. Stereotactic radiosurgery alone
C. Surgical resection
D. Observation
E. Embolization and stereotactic radiosurgery

Answer 53

D. Observation

The Spetzler-Martin arteriovenous malformation (AVM) grading system is based on AVM size (1 to 3 points allocated for an < 3 cm, 3 to 6 cm, and > 6 cm, respectively), eloquence of adjacent brain
(eloquent, 1 point; non-eloquent, 0 points), and
venous drainage (deep, 1 point; superficial, 0 points).
The natural history of the disease process (3 to 4%
risk of hemorrhage yearly) must be considered with
the risk of treatment. Grade 4 and 5 AVMs often
are treated with serial scans and observation. The
described AVM is grade 5.

Question 54

After elective clipping of an unruptured anterior
communicating artery aneurysm, the patient wakes
up with dysarthria and contralateral paresis of his
face and arm. What vessel likely is incorporated
into the aneurysm clip?
A. Anterior choroidal artery
B. Recurrent artery of Heubner
C. Middle cerebral artery
D. Distal anterior cerebral artery

Answer 54

B. Recurrent artery of Heubner

The Recurrent artery of Heubner typically originates from the proximal A2 segment of the anterior
cerebral artery. It supplies the head of the caudate
nucleus, anterior limb of the internal capsule,
anterior putamen, and globus pallidus. Unilateral
injury results in contralateral face and arm weakness. Bilateral injury results in akinetic mutism.
(A) The anterior choroidal artery supplies the posterior limb of the internal capsule and the lateral
geniculate body of the thalamus. Occlusion results
in contralateral hemiplegia, hemianesthesia, and
homonymous visual field deficits. (C) Injury to the
middle cerebral artery results in an infarct causing
contralateral hemiparesis and neglect. (D) Distal
anterior cerebral artery compromise results in
infarcts in the paramedian cortex.

Question 55

The most common primary, intra-axial posterior
fossa tumor in adults is associated with what
condition?
A. Smoking
B. Tumor suppressor gene inactivation on chro-
mosome 9q34
C. Tumor suppressor gene inactivation on chro-
mosome 7q21
D. Tumor suppressor gene inactivation on chro-
mosome 3p25

Answer 55

D. Tumor suppressor gene inactivation on chro-
mosome 3p25

The most common posterior fossa tumor in
adults is metastases (most often from lung cancer); however, the most common primary, intraaxial posterior fossa tumor is hemangioblastoma.
Von Hippel–Lindau syndrome is associated with
30% of cerebellar hemangioblastomas and is an
autosomal dominant, inherited disease found on
chromosome 3p25. (A) Smoking is most associated
with metastatic lesions. (B) Tumor suppressor
gene inactivation on chromosome 9q34 is associated with tuberous sclerosis. (C) Tumor suppressor
gene inactivation on chromosome 7q21 is associated with a familial form of cavernomas.

Question 56

A 21-year-old man presents with a brachial plexus
avulsion type injury. What is the recommended
treatment option?
A. Periodic electromyography/nerve conduction studies starting 3 to 12 weeks following the injury with consideration of surgical neu-rotization at 3 to 6 months if there is no improvement
B. Periodic electromyography/nerve conduction
studies starting 3 to 12 weeks following the
injury with consideration of surgical neu-
rolysis at 3 to 6 months if there is no
improvement
C. Periodic electromyography/nerve conduction
studies starting 3 to 12 weeks following the
injury with consideration of a spinal cord
stimulator if pain remains after 3 to 6 months
D. Exploration and surgical repair within 3 days
E. Exploration at 2 to 3 weeks

Answer 56

A. Periodic electromyography/nerve conduction studies starting 3 to 12 weeks following the injury with consideration of surgical neu-rotization at 3 to 6 months if there is no improvement

Surgical treatment of peripheral nerve injuries
can be defined by the “rule of 3’s.” Sharp lacerations are explored within 3 days, penetrating injuries are explored in 2 to 3 weeks, and gunshot
wounds and traction injuries are explored in 3 to 6
months. An avulsion (traction injury) occurs when
a root is pulled from the spinal cord with no chance
of reinnervation. Because this injury happens proximal to the dorsal root ganglia, synaptic action potentials are characteristically normal. Neurolysis
(lysis of scar tissue) is not successful for lesions
that are not in continuity. A dorsal root entry zone
(DREZ) lesioning procedure is the procedure of
choice for chronic pain for plexus avulsion injuries.
Only neurotization (nerve transfers) can restore
downstream nerve/muscle/sensory function.

Question 57

What type of basal skull fracture is associated with
an increased risk of mortality?
A. Longitudinal temporal bone fracture
B. Transverse temporal bone fracture
C. Fracture through the planum sphenoidale
D. Clival fracture

Answer 57

D. Clival fracture

Clival fractures can be longitudinal, transverse, or
oblique and are highly fatal due to associated injuries and to an elevated risk of meningitis. (A) Longitudinal temporal bone fractures are common and
usually run parallel to the external auditory canal.
They often spare the facial and vestibulocochlear
nerves but may involve ossicular chain. (B) Transverse temporal bone fractures often pass through
the cochlea and may stretch the geniculate ganglion, causing facial and vestibulocochlear nerve
palsies. (C) Fractures of the anterior fossa (planum
sphenoidale) can injure the optic nerves if the fractures extend into the optic canals. Severe fractures
may produce shearing injuries of the pituitary gland.

Question 58

During decompression of an ulnar nerve, the sur-
geon wishes to ensure that the nerve is decom-
pressed distally. The ulnar nerve can be found
entering the forearm in relation to what structure?
A. Deep to the pronator teres
B. Deep to the flexor carpi radialis
C. Deep to the flexor digitorum profundus
D. Lateral to the ulnar artery
E. Between the two heads of the flexor carpi ulnaris

Answer 58

E. Between the two heads of the flexor carpi ulnaris

The ulnar nerve enters the forearm by passing
between and then deep to the two heads of the
flexor carpi ulnaris. (A) For transpositions of the
ulnar nerve, the pronator teres is sectioned.
(C) The ulnar nerve lies on the surface of flexor
digitorum profundus. (D) The ulnar nerve lies
medial to the ulnar artery in the forearm.

Question 59

During a carotid endarterectomy, what is the cor-
rect order of vessel occlusion?
A. External, common, and then internal carotid
artery
B. Internal, common, and then external carotid artery
C. Common, internal, and then external carotid
artery
D. Internal, external, and then common carotid
artery
E. External, internal, and then common carotid
artery

Answer 59

B. Internal, common, and then external carotid artery

The goal of vessel occlusion is to force any
embolus/thrombus, if present, into the external
carotid artery. The mnemonic for the clamping
order is “ICE”: internal, common, external carotid
artery. The order for releasing the vessels is the
reverse.

Question 60

A 63-year-old woman presents with ruptured
anterior communicating artery aneurysm and an
intracranial hemorrhage in the gyrus rectus. What
is her Fisher grade?
A. 0
B. 1
C. 2
D. 3
E. 4

Answer 60

E. 4

Fisher grading correlates the amount of blood on
CT scan with the risk of vasospasm and is graded
from 1 to 4: grade 1, no subarachnoid hemorrhage; grade 2, diffuse/vertical layer of subarachnoid hemorrhage less than 1 mm in thickness;
grade 3, hemorrhage of 1 mm or more; grade 4,
intracranial or intraventricular hemorrhage regardless of subarachnoid hemorrhage thickness. Thick,
cisternal subarachnoid hemorrhage has the highest risk for vasospasm (grade 3 or 4).

Question 61

What approach characterizes a far lateral
craniotomy?
A. Suboccipital craniotomy including opening of
the foramen magnum and drilling of the
occipital condyle
B. Suboccipital craniotomy with exposure of the
transverse and sigmoid sinus
C. Suboccipital craniotomy with pre- and post-
sigmoid exposure
D. Subtemporal craniotomy with removal of the
petrous apex
E. Retrosigmoid craniotomy with removal of the
lamina of C1 and C2

Answer 61

A. Suboccipital craniotomy including opening of
the foramen magnum and drilling of the
occipital condyle

The far lateral approach and its associated craniotomies (transcondylar, transjugular, etc.) often
involve removing the subocciput extending down
into the foramen magnum as well as trying to
achieve a more lateral exposure by drilling the occipital condyle.

Question 62

What characteristics (location and size) of a cere-
bral abscess are a surgical indication?
A. Subcortical location; 2.5 cm in diameter
B. Brainstem location; 1.0 cm in diameter
C. Small lesion in the early cerebritis stage; 0.5
cm in diameter
D. Periventricular location; 2.0 cm in diameter

Answer 62

D. Periventricular location; 2.0 cm in diameter

Surgical management of a cerebral abscess should
be considered for large lesions with mass effect, in
order to establish a diagnosis, and in the following
situations: increased intracranial pressure, poor
neurologic condition, association with foreign
material, abscesses that are fungal in origin, multiloculated abscesses, and abscesses in close proximity to the ventricular system. The latter finding is
due to the poor outcome following intraventricular
abscess rupture. Often, an abscess 3 cm or larger is
deemed more appropriate for surgical management, whereas smaller abscesses may be responsive to medical therapy alone

Question 63

A patient presents with subarachnoid hemorrhage
due to a ruptured aneurysm. What is the approxi-
mate risk of re-rupture over the next 14 days if the
aneurysm is not treated?
A. 1 to 2%
B. 5 to 10%
C. 15 to 20%
D. 50%
E. 75%

Answer 63

C. 15 to 20%

Although many factors play a role in prognosticating re-rupture risk, overall, the risk of aneurysm re-rupture is 4% on the first day and then 1 to
1.5% per day for the next 13 days. This equates to
an approximately 15 to 20% risk of re-rupture over
the first 14 days. There is a 50% risk of re-rupture
over the first 6 months, and a 3% risk per year after
that.

Question 64

What is the most definitive treatment for atonic
seizures?
A. Ethosuximide
B. Adrenocorticotropic hormone
C. Multiple subpial transections
D. Hemispherectomy
E. Corpus callosotomy

Answer 64

E. Corpus callosotomy

A corpus callosotomy may be most effective as
a treatment for generalized major motor seizures
and is used for atonic seizures where the loss
of postural tone can result in falls/injuries (70%
reduction in seizures expected with the procedure), unilateral hemispheric damage resulting in
generalized seizures, Lennox-Gastaut syndrome,
and, in some patients, generalized seizures without a resectable focus. (A) Ethosuximide is used
for absence seizures. (B) Adrenocorticotropic hormone can be used for West syndrome in which
electroencephalography reveals hypsarrhythmias.
(C) Subpial transections are used for partial seizure
originating in cortical areas. (D) Hemispherectomy
is used for unilateral seizures with widespread
hemispheric lesions and profound contralateral
deficits (e.g., Rasmussen syndrome).

Question 65

What is the most effective thalamic target during
deep brain stimulation to control tremor associated
with Parkinson disease?
A. Medial nucleus
B. Ventralis intermedius nucleus
C. Nucleus accumbens
D. Anterior nucleus
E. Pedunculopontine nucleus

Answer 65

B. Ventralis intermedius nucleus

The ventrolateral nucleus is composed of the
ventralis intermedius and ventralis oralis nuclei.
This also is an effective target when attempting to
control essential tremor. (A) The medial nucleus
is a target for obsessive compulsive disorder as
are the bilateral internal capsules. (C) The nucleus
accumbens is an investigational target for treatment of depression, obesity, and anorexia. (D) The
anterior nucleus is a potential target for epilepsy.
(E) The pedunculopontine nucleus has been used as
a target for movement disorders that are primarily
posture and gait related.

Question 66

How is the C7 plumb line measured?
A. Originates at the posterior vertebral body of
C7 and is measured from the anterior verte-
bral body of S1
B. Originates at the mid-vertebral body of C7 and
is measured from the mid-vertebral body of S1
C. Originates at the mid-vertebral body of C7 and
is measured from the posterior superior cor-
ner of S1
D. Originates at the anterior vertebral body of C7
and is measured from the mid-vertebral body
of S1
E. Originates at the anterior vertebral body of C7
and is measured from the anterior vertebral
body of S1

Answer 66

C. Originates at the mid-vertebral body of C7 and
is measured from the posterior superior cor-
ner of S1

The C7 plumb line is created by dropping a vertical line from the mid-C7 vertebral body. The distance between the C7 plumb line and the posterior
superior corner of the S1 vertebral body is measured, and helps to determine the sagittal balance
of the patient. The ideal measurement is < 5 cm
on either side of the plumb line, as this facilitates
a level gaze and prevents falling. Of note, the C7
plumb line approximates the clivus.

Question 67

A patient with L4/L5 degenerative spondylolisthe-
sis presents with radiculopathy. The L4 vertebral
body is approximately 60% anterolisthesed. What
grade is this spondylolisthesis according to the
Meyerding grading scale?
A. Grade 1
B. Grade 2
C. Grade 3
D. Grade 4
E. Grade 5

Answer 67

C. Grade 3

Grade 3 spondylolisthesis is 50 to < 75% anterolisthesis. (A) Grade 1 spondylolisthesis is < 25% anterolisthesis. (B) Grade 2 spondylolisthesis is
25 to < 50% anterolisthesis. (D) Grade 4 spondylolisthesis is 75% or more anterolisthesis. (E) There
is no grade 5 spondylolisthesis. Anterolisthesis of
100% or more is termed spondyloptosis.

Question 68

A middle-aged woman presents to the emergency
room with complaints of a sudden onset of the
“worst headache of my life.” She complains of
photophobia and nuchal rigidity. The head CT was
negative for subarachnoid hemorrhage, and the
CT angiogram did not reveal an aneurysm. What
would be the most reasonable next step in this
patient’s management?
A. Discharge the patient home with pain
medications.
B. Admit the patient with aneurysm precautions,
and repeat the CT angiogram in 5 to 7 days.
C. Obtain a lumbar puncture.
D. Repeat the head CT in 4 to 6 hours.
E. Obtain a brain MRI.

Answer 68

C. Obtain a lumbar puncture.

A head CT can detect subarachnoid hemorrhage
in more than 95% of cases; however, a lumbar
puncture is the most sensitive test for subarachnoid hemorrhage. Although traumatic taps can
result in false positives, non-clotting bloody fluid
that does not clear with sequential tubes (usually
RBC more than 100,000) and xanthochromia (the
yellow coloration of cerebrospinal fluid supernatant
after centrifuging) suggest subarachnoid hemorrhage. Spectrophotometry is more sensitive than
visual inspection of cerebrospinal fluid for xanthochromia, but xanthochromia typically does not
become apparent until 2 to 4 hours following subarachnoid hemorrhage and is seen in almost 100%
of patients 12 hours after subarachnoid hemorrhage. (A) Given the clinical symptomatology, it
is important to rule out completely the suspected
aneurysm. (E) MRI is not sensitive for the first 24
to 48 hours after subarachnoid hemorrhage but
is good for revealing subacute blood. If there is a
high degree of clinical suspicion for an aneurysm,
a cerebral angiogram may be a reasonable imaging modality.

Question 69

This diagram attempts to define which parameter?
A. Sacral slope
B. Pelvic tilt
C. Pelvic incidence
D. Sagittal vertical axis
E. T1 tilt

Answer 69

B. Pelvic tilt

Pelvic tilt is the angle measurement between a
line drawn from the midpoint of the S1 end plate
to the midpoint of the femoral head and a vertical
line from the femoral axis. It represents a “compensatory mechanism”; thus, patients with kyphotic
deformities may use retropulsion to keep their
head aligned with the horizon. Increasing retroversion to accommodate for increasing kyphosis
will increase the pelvic tilt. (A) Sacral slope is the
measurement of the sacral slant, and is the angle
between a line parallel to the sacral end plate and
the horizon. (C) Pelvic incidence = Pelvic tilt +
Sacral slope. Sacral slope approximates the pelvic
incidence. Pelvic incidence is the angle measurement between the line from the mid-femoral head
to the midpoint of the sacral end plate and a line
perpendicular to the sacral end plate. This parameter does not change.

Question 70

In the repair of peripheral nerve lesions with large
gaps, the standard graft material is:
A. Autologous anterior interosseus nerve
B. Autologous sural nerve
C. Silicone
D. Cadaveric nerve
E. Autologous vein

Answer 70

B. Autologous sural nerve

The ideal donor nerve provides a suitable environment for regeneration and results in acceptable
donor morbidity. It should be of sufficient length,
easy to locate, surgically accessible, and have well
developed fascicles. Although sural nerve harvesting does result in a sensory deficit in the lateral leg,
it generally is well tolerated. In addition, its length
allows for bridging of large gaps. (A) Although motor
nerves make better grafts than sensory nerves,
there typically would be significant morbidity with
a harvest of the anterior interosseous nerve. The
anterior interosseous nerve typically is not used,
given its motor function, although the terminal
branch of the posterior interosseous nerve has been
used for distal digital nerve grafts. (D) Allograft
(acellularized) nerve material can bridge sensory
but not motor nerve gaps up to 4 cm. (E) Vein
grafts utilize the concept of hollow tubes, but
superiority over conventional nerve grafting has
not been established

Question 71

During a percutaneous trigeminal radiofrequency
rhizotomy for a patient with trigeminal neuralgia,
after inserting the electrode into the oral mucosa,
the initial trajectory is:
A. Toward a point on a line intersecting the ex-
ternal auditory meatus and medial aspect of
the pupil
B. Toward a point on a line intersecting 3 cm
anterior to the external auditory meatus and
medial aspect of the pupil
C. Toward a point on a line intersecting the exter-
nal auditory meatus and contralateral medial
aspect of the pupil
D. Toward a point on a line intersecting the clivus
and posterior clinoid
E. Toward a point > 8 mm beyond the clival line

Answer 71

B. Toward a point on a line intersecting 3 cm
anterior to the external auditory meatus and
medial aspect of the pupil

During a percutaneous trigeminal radiofrequency
rhizotomy, the electrode is placed in a plane intersecting a point 3 cm anterior to the external auditory meatus and medial aspect of the pupil when
the eye is directed forward. The tip is advanced
toward the intersection of the petrous bone and
clivus (5 to 10 mm inferior to the sella) keeping the
needle < 8 mm from the clival line to avoid cranial
nerve II or VI complications.

Question 72

With regard to vertebral artery injury and C2
neuralgia, what is the difference (if any) between
utilizing a C1 lateral mass–C2 pedicle/pars screw
construct for C1 to C2 fixation versus placement of
transarticular screws?
A. Less chance of vertebral artery injury and C2
neuralgia with transarticular screw fixation
compared with the C1 lateral mass–C2 pedicle/
pars screw approach
B. Less chance of vertebral artery injury and
more C2 neuralgia with transarticular screw
fixation compared with the C1 lateral mass–
C2 pedicle/pars screw approach
C. More chance of vertebral artery injury and C2
neuralgia with transarticular screw fixation
compared with the C1 lateral mass–C2 pedicle/
pars screw approach
D. More chance of vertebral artery injury and less
C2 neuralgia with transarticular screw fixa-
tion compared with the C1 lateral mass–C2
pedicle/pars screw approach
E. Same chance of vertebral artery injury with
both approaches with more C2 neuralgia with
the C1 lateral mass–C2 pedicle/pars approach

Answer 72

D. More chance of vertebral artery injury and less
C2 neuralgia with transarticular screw fixa-
tion compared with the C1 lateral mass–C2
pedicle/pars screw approach

Some advantages of a C1 lateral mass–C2 pedicle/
pars screw fixation approach include the fact that
anatomic alignment during screw placement is not
necessary, in that manipulation can be performed
after screw placement and before rod insertion. In
addition, the method is associated with a reduced
risk of vertebral artery injury compared with the
transarticular approach. This is due to the ability
to place screws despite aberrant vertebral artery
anomalies partially due to the more superior and
medial trajectories of C2 pedicle screws. Unfortunately, there tends to be more C2 neuralgia with
the C1 lateral mass–C2 pedicle/pars screw approach.

Question 73

A 29-year-old woman underwent a cervical lymph
node biopsy for persistent lymphadenopathy. Post-
operatively, she complained of an inability to abduct
her arm. What condition is suspected?
A. Hysteria
B. Carotid injury and stroke
C. Injury to the C5 nerve root
D. Injury to the spinal accessory nerve
E. Injury to the long thoracic nerve

Answer 73

D. Injury to the spinal accessory nerve

Injury to the spinal accessory nerve during dissection of the posterior triangle of the neck is a
well-known complication of lymph node biopsy.
(B) A carotid injury and stroke would manifest
with additional symptoms, and the carotid artery
is not found in the posterior triangle of the neck.
(C) Injury to the C5 nerve root and deltoid weakness can cause an inability to abduct the shoulder,
but the C5 root is not found in the posterior triangle of the neck. (E) Damage to the long thoracic
nerve causes a serratus anterior weakness and
winged scapula and can occur with blunt trauma,
over-stretching, and lifting excessive weight over
the shoulder. It does not occur with dissection of
the posterior triangle of the neck.

Question 74

A 61-year-old woman presents with an acute,
severe headache with nausea and vomiting. CT of
the brain revealed cisternal subarachnoid hemor-
rhage. Cerebral angiography revealed an aneurysm
not amenable to coiling. The patient was taken for
an open craniotomy and clipping of the aneurysm.
After surgery, the patient was noted to have an
oculomotor nerve palsy. Where was the patient’s
aneurysm most likely located?
A. At the internal carotid artery bifurcation
B. At the origin of the posterior inferior cere-
bellar artery
C. At the middle cerebral artery most proximal
bifurcation
D. At the junction of the anterior cerebral artery
A1 segment and anterior communicating artery
E. At the junction of the basilar and superior cer-
ebellar arteries

Answer 74

E. At the junction of the basilar and superior cer-
ebellar arteries

Cranial nerve III palsies often are associated with
posterior communicating artery aneurysms, but
oculomotor nerve palsy is one of the most frequent
complications following surgical treatment of distal basilar artery aneurysms. The incidence of cranial nerve III palsies following surgery ranges from
25 to 80%, although many spontaneously resolve.
There is a higher incidence of such a palsy with
superior cerebellar artery aneurysms. (B) Lower
cranial nerve palsies as well as lateral medullary
syndrome (depending on surgical approach) can
be seen following surgery for posterior inferior
cerebellar artery aneurysms. (C) Complications
of middle cerebral artery aneurysm surgery can
include contralateral weakness. (D) A concern
during anterior cerebral artery aneurysm surgery
is the accidental sacrifice of perforators to the
optic apparatus, which would cause visual loss but
not an oculomotor palsy.

Question 75

The most common deficit associated with a corpus
callosotomy is:
A. Intracerebral hemorrhage
B. Hyperthermia
C. Memory problems
D. Speech irregularities
E. Visual problems

Answer 75

D. Speech irregularities

Speech irregularities including mutism can occur
with sectioning of the corpus callosum. Other complications include “alien hand” and supplemental
motor area syndromes. Most disconnection deficits are not present as long as the splenium is
spared. If there is injury to the anterior cerebral
arteries, strokes and lower extremity weakness
can occur. Retraction during a corpus callosotomy
also can lead to postoperative sensory and motor deficits. (C) Memory problems can occur during
transcallosal approaches and are attributable to
injuries to the fornix.

Question 76

A 52-year-old man presents to the emergency room
after a fall from his porch. The neurologic exam
shows weakness more pronounced in the upper
extremities compared with the lower extremities,
with distal weakness greater than proximal weak-
ness. Imaging suggests severe cervical stenosis with
an associated cord signal change. After 24 hours,
the patient’s neurologic exam is worse. What is the
appropriate next step in the treatment of this
patient?
A. High-dose steroid administration
B. Bracing and physical therapy
C. Surgical decompression with or without
fixation
D. Dynamic radiographs to rule out instability
E. Neurology service consultation

Answer 76

C. Surgical decompression with or without
fixation

Indications for surgical intervention in patients
with central cord syndrome include persistent
stenosis/cord compression with significant fixed
motor deficits or progressive dysfunction, spinal
instability, or potentially intractable pain. (A) The
high-dose steroid protocol utilized in the NASCIS
trial consisted of a 30 mg/kg bolus of methylprednisolone followed by 5.4 mg/kg/h for 24 or 48 hours.
This treatment is controversial. (D) Although an
unstable cervical spine may lead to the development of central cord syndrome and require surgical
fixation, decompression is the mainstay of treatment options with central cord syndrome.

Question 77

A man incurs an injury to the musculocutaneous
nerve during a car accident. Three months follow-
ing the accident, the electrophysiological studies
of the patient’s biceps show fibrillations and motor
unit potentials. What is this patient’s Sunderland
peripheral nerve injury classification?
A. First degree
B. Second or third degree
C. Fourth degree
D. Fifth degree

Answer 77

B. Second or third degree

With a second- or third-degree injury, there is
axonal discontinuity. A third-degree injury also has
disruption of the endoneurium. Fibrillations are
seen with both degrees of injury, and motor unit
potentials (MUPs) are present but abnormal. Surgery may be indicated for successful repair, and
this is an axonotmesis. Axonal regeneration occurs
at a rate of about 1 mm per day. (A) A first-degree
injury results in segmental demyelination. Fibrillations are not seen, and MUPs are normal. Surgery
is not indicated, as this is only a neurapraxia. (C) A
fourth-degree injury results in a loss of axon continuity and endoneurial tubes, along with the endoneurium and perineurium. The epineurium remains
intact. Fibrillations and MUPs are not seen. Surgery is indicated for successful repair, and this is
an axonotmesis. (D) A fifth-degree injury equates
to nerve transection with all structures including
the epineurium losing continuity. Fibrillations and
MUPs are not seen. Surgery is indicated for successful repair, as this is a neurotmesis.

Question 78

A punctate midline myelotomy can be valuable
for patients with intractable pain associated with
malignancy in the abdominal or pelvic regions. A
myelotomy for these purposes commonly is per-
formed at what spinal level?
A. L2
B. T2
C. T8
D. T10
E. T12

Answer 78

C. T8

A punctate midline myelotomy (5-mm depth)
at the T8 level generally is successful in the management of intractable pain associated with malignancy in the abdominal or pelvic regions. This level
is remote from the spinal segments innervated by
afferents of the lower abdomen.

Question 79

Anterior choroidal artery aneurysms usually have
what orientation compared to the parent vessel?
A. Oriented superiorly/superolaterally
B. Oriented medially
C. Oriented inferiorly/inferomedially
D. Oriented anteriorly
E. Oriented posteriorly

Answer 79

A. Oriented superiorly/superolaterally

Question 80

How much of the superior sagittal sinus can be
sacrificed without a high risk of inducing venous
infarctions?
A. Anterior two thirds
B. No more than one third of any portion
C. Anterior one third
D. Entire sinus as long as the cortical bridging
veins are left intact
E. None of the sinus but all of the cortical bridg-
ing veins can be sacrificed without risk of
venous infarctions.

Answer 80

C. Anterior one third

Only the anterior one third of the superior sagittal sinus can be sacrificed without risk of venous
infarctions. The risk increases greatly if any amount
of the sinus is sacrificed distal to the anterior one
third along with extensive sacrifice of the cortical
bridging veins

Question 81

A man presents with an infarct of the artery of
Percheron. What are his expected deficits?
A. Obtundation, coma, variable degrees of hemi-
plegia or hemisensory loss, a vertical gaze
palsy, and memory impairment
B. Hemiparesis, hemisensory loss, and a homon-
ymous hemianopsia
C. Hemiparesis of the upper extremity and face,
dysarthria, and hemichorea
D. A cranial nerve III palsy, Parinaud syndrome,
abulia, and somnolence
E. Ipsilateral sensory loss in the face and contra-
lateral sensory loss in the body without pyra-
midal findings or a change in sensorium

Answer 81

A. Obtundation, coma, variable degrees of hemi-
plegia or hemisensory loss, a vertical gaze
palsy, and memory impairment

The artery of Percheron arises from the proximal segment of the posterior cerebral artery and
supplies blood to the paramedian thalamus and
rostral midbrain bilaterally. The triad of bilateral
paramedian thalamic infarcts consists of altered
mental status, a vertical gaze palsy, and memory
impairment. (B) Hemiparesis, hemisensory loss,
and a homonymous hemianopsia are seen with an
anterior choroidal artery infarct. (C) Hemiparesis
of the upper extremity and face, dysarthria, and
hemichorea are seen with a recurrent artery of
Heubner (medial striate artery) stroke. (D) A cranial nerve III palsy, Parinaud syndrome, abulia, and
somnolence are seen in mesencephalothalamic
syndrome or “top of the basilar artery” syndrome.
(E) Ipsilateral sensory loss in the face and contralateral sensory loss in the body without pyramidal
findings or a change in sensorium are seen with
lateral medullary syndrome. Patients also experience vertigo, nausea, vomiting, nystagmus, diplopia, ataxia, Horner syndrome, and dysphagia.

Question 82

What pain procedure is best for pelvic visceral can-
cer pain?
A. Dorsal root entry zone lesioning
B. C1-C2 cordotomy
C. Spinal cord stimulation
D. Selective dorsal rhizotomy
E. Midline myelotomy

Answer 82

E. Midline myelotomy

Visceral cancer pain in the pelvic and rectal area
is relayed through a midline pathway in the dorsal
columns. Punctate midline myelotomies have been
shown to alleviate visceral cancer pain.

Question 83

What pain procedure is best for intractable severe
upper extremity cancer pain?
A. Dorsal root entry zone lesioning
B. C1-C2 cordotomy
C. Spinal cord stimulation
D. Selective dorsal rhizotomy
E. Midline myelotomy

Answer 83

B. C1-C2 cordotomy

The spinothalamic tract is divided at the level of
C1-C2. A cordotomy at this level is reserved for intractable severe upper extremity pain due to cancer. Side
effects include dysesthesia, urinary retention, sleep
apnea, and weakness.

Question 84

What pain procedure is best for diplegic spasticity?
A. Dorsal root entry zone lesioning
B. C1-C2 cordotomy
C. Spinal cord stimulation
D. Selective dorsal rhizotomy
E. Midline myelotomy

Answer 84

D. Selective dorsal rhizotomy

A selective dorsal rhizotomy is performed on the
lower spinal cord and is best for diplegic spasticity.
It is used primarily in treating children with cerebral palsy with lower extremity spasticity who have
borderline ambulation abilities. (A) Dorsal root
entry zone lesioning is most beneficial in nerve
avulsion pain such as that of the brachial plexus or
in transitional zone pain following spinal cord injury. The procedure should be reserved for patients
who have shown no evidence of functional recovery
of the affected nerve. (C) Spinal cord stimulation is
useful in treating neuropathic leg pain following
failed back surgery, mainly in cases where imaging
does not show a compressive lesion impinging on
any neural structures. The most appropriate level
for implantation is at T10-T11.

Question 85

When accessing the third ventricle through a tran-
scallosal, transchoroidal surgical approach, what
layers, in order, are passed through as the roof of
the third ventricle is traversed?
A. Fornix, vascular layer, superior layer of the tela
choroidea, inferior layer of the tela choroidea,
choroid of the third ventricle
B. Superior layer of the tela choroidea, fornix,
vascular layer, choroid plexus of the third ven-
tricle, inferior layer of the tela choroidea
C. Superior layer of the tela choroidea, fornix,
vascular layer, inferior layer of the tela cho-
roidea, choroid plexus of the third ventricle
D. Choroid plexus of the third ventricle, superior
layer of the tela choroidea, vascular layer, for-
nix, inferior layer of the tela choroidea
E. Fornix, superior layer of the tela choroidea,
vascular layer, inferior layer of the tela cho-
roidea, choroid plexus of the third ventricle

Answer 85

E. Fornix, superior layer of the tela choroidea,
vascular layer, inferior layer of the tela cho-
roidea, choroid plexus of the third ventricle

The correct layers of the roof of the third ventricle, from superficial to deep, are the body of the
fornix, superior layer of the tela choroidea, vascular layer, inferior layer of the tela choroidea, and
choroid plexus of the third ventricle.

Question 86

A 40-year-old man presented to the emergency
room with complaints of left-hand numbness. Fur-
ther workup revealed the lesion on MRI that is
shown in this image. He was taken to surgery for
resection. Postoperatively, the patient awoke with
a dense left hemiparesis. Supplementary motor
area (SMA) syndrome was suspected. What is the
expected prognosis of SMA syndrome?
A. Permanent left hemiparesis/hemiplegia
B. Temporary decreased spontaneous and volun-
tary movements of the left upper and lower
extremities with spontaneous recovery
C. Permanent decreased spontaneous and volun-
tary movements of the left upper and lower
extremities with aphasia without spontaneous
recovery
D. Temporary left lower extremity paresis with
loss of muscle tone with spontaneous recovery
E. Temporary left upper and lower extremity
paresis and hemisensory loss with spontaneous
recovery

Answer 86

B. Temporary decreased spontaneous and volun-
tary movements of the left upper and lower
extremities with spontaneous recovery

Supplementary motor area (SMA) syndrome
characteristically causes a contralateral apraxia and
loss of spontaneous/voluntary movements, with
preservation of muscle tone and strength. It can
result in mutism occurring more often when the
dominant SMA is involved. Reflexes often are preserved. Classically, there is spontaneous recovery
over weeks to months, leaving only a long-term
deficit in alternating bimanual movements.

Question 87

A 63-year-old man wakes from anesthesia follow-
ing an anterior cervical diskectomy and fusion
(ACDF). Postoperatively, he complains of unilateral
blurry vision, and ptosis is noted on the same side.
What is the most common cause of Horner syn-
drome following an ACDF?
A. Retractor placement
B. Carotid dissection
C. Recurrent laryngeal nerve injury
D. Vertebral artery injury

Answer 87

A. Retractor placement

Injury to the cervical sympathetic trunk (CST)
can lead to Horner syndrome. The CST is located in
the fascia over the longus colli muscle 10 to 15 mm
lateral from the medial edge of the muscle. It is
most medial at C6; therefore, it is more prone to
injury during lower cervical surgery. During retractor placement, if the tip of the retractor blade
slips out from between the medial edge of the longus colli muscle and the vertebral body, injury can
occur to the CST. (B) During the exposure for an
anterior cervical diskectomy and fusion, the carotid
sheath is encountered; however, careful attention
and ensuring that the dissection is medial to the
carotid sheath prevents injuries. (C) Injury to the
recurrent laryngeal nerve results in hoarseness,
and not Horner syndrome. (D) A vertebral artery
injury would result in Wallenberg syndrome or lateral medullary stroke symptoms, and not Horner
syndrome.

Question 88

In the event of trauma, what finding on a skull
radiograph best indicates the possible need for
emergent surgical intervention?
A. Fluid level in the sphenoid sinus
B. Pneumocele
C. Double density sign
D. Fluid level in the frontal sinus
E. Linear temporal fracture

Answer 88

E. Linear temporal fracture

(A–E) All of these findings can be seen on skull
radiographs and can indicate trauma and the need
for possible surgical intervention. Nevertheless, a
temporal skull fracture can cause injury to the
middle meningeal artery with the subsequent development of an epidural hematoma. A skull fracture is present in about 80 to 95% of all epidural
hematomas, and about 24% of all skull fractures
are associated with an epidural hematoma. (A) A
fluid level in the sphenoid sinus may indicate a
basal skull fracture. (B) A pneumocele may be
indicative of a fracture with a dural tear. (C) The
presence of a double density sign (if confirmed on
AP and lateral imaging) may indicate a depressed
skull fracture. (D) A fluid level in the frontal sinus
may indicate a frontal sinus fracture.

Question 89

According to the Asymptomatic Carotid Artery
Stenosis (ACAS) trial, what are the recommenda-
tions regarding performing a carotid endarterec-
tomy (CEA)?
A. There is a moderate benefit to performing an
immediate CEA compared with medical man-
agement in patients under 75 years of age
with asymptomatic carotid stenosis > 60%.
B. Patients with symptomatic moderate (50 to
69%) and severe (≥ 70%) carotid stenosis should
be considered for a CEA.
C. Carotid stenting and CEA are associated with
similar rates of death and disabling strokes,
with an increased stroke incidence associated
with stenting and an increased myocardial in-
farction incidence associated with CEA.
D. Patients with carotid stenosis > 80% or symp-
tomatic lesions > 50% and who are at high risk
for surgery have equal outcomes when treated
by stenting compared with a CEA.
E. In patients with good health and asymptom-
atic carotid stenosis > 60%, a CEA is beneficial
if the surgeon maintains perioperative mor-
bidity/mortality rates less than 3%.

Answer 89

E. In patients with good health and asymptom-
atic carotid stenosis > 60%, a CEA is beneficial
if the surgeon maintains perioperative mor-
bidity/mortality rates less than 3%.

rates less than 3%.
(A) This conclusion is derived from the Asymptomatic Carotid Surgery Trial (ACST). This trial did
not substantiate what was found previously in
terms of benefiting women with asymptomatic
carotid stenosis by performing a carotid endarterectomy (CEA). (B) This conclusion is derived from the
North American Symptomatic Carotid Endarterectomy Trial (NASCET). (C) This conclusion is derived from the Carotid Revascularization Endarterectomy
versus Stenting Trial (CREST) that demonstrated
that stenting may be an option for carotid stenosis
but is not superior to a CEA. This finding makes
stenting attractive for patients with advanced age,
poor surgical anatomy, previous radiation, or significant comorbidities. (D) This finding is from
the Stenting and Angioplasty with Protection in
Patients at High Risk for Endarterectomy (Sapphire)
trial, which is a noninferiority trial for patients with
carotid stenosis and who have a high surgical risk.

Question 90

During a subtemporal approach, the greater super-
ficial petrosal nerve often is divided. What deficit
is expected upon sectioning this nerve?
A. Decreased salivation
B. Miosis
C. Decreased tearing
D. Mydriasis
E. Hyperacusis

Answer 90

C. Decreased tearing

The greater superficial petrosal nerve (GSPN)
emerges from the facial nerve distal to the geniculate ganglion and carries preganglionic parasympathetic fibers. It innervates the nasal and palatine
mucosa and the lacrimal gland of the eye; thus, sectioning of the GSPN may cause decreased tearing
when it is sectioned. (A) The otic and submandibular ganglia innervate the parotid/submandibular
glands for salivation. (B, D) The facial nerve does
not control pupillary diameter. (E) Hyperacusis
can develop after damage to the tympanic branch
of the facial nerve, which innervates the stapedius
muscle.

Question 91

What is/are the contraindication(s) for traction
with a cervical spine injury?
A. Atlanto-occipital dislocation and a type 2A
hangman fracture
B. C4/C5 locked facets and a type 2A hangman
fracture
C. Atlantoaxial rotatory subluxation and a type
2A hangman fracture
D. Atlanto-occipital dislocation and atlantoaxial
rotatory subluxation
E. C4/C5 locked facets and atlantoaxial rotatory
subluxation

Answer 91

A. Atlanto-occipital dislocation and a type 2A
hangman fracture

Traction may worsen a deficit with an atlantooccipital dislocation. It also may cause increased
angulation and widening of the disk space in a
type 2A hangman fracture (an angulated and distracted fracture). Traction often is used in an
attempt to reduce locked facets in neurologically
intact patients able to participate in neurologic
testing.

Question 92

After what age does the chance of a spontaneous
subarachnoid hemorrhage become more likely to
be due to an aneurysm than due to an arterio-
venous malformation?
A. 18 years old
B. 30 years old
C. 45 years old
D. 55 years old
E. 68 years old

Answer 92

A. 18 years old

Question 93

A 67-year-old woman presents to the emergency
room following a motor vehicle collision with a
large right-sided subdural hematoma and uncal
herniation seen on CT. The Glasgow Coma Scale
score is 5. She has a dilated and nonreactive right
pupil. She has flexor posturing on the left side and
is hemiplegic on the right side. What is the most
likely explanation for her right-sided hemiplegia?
A. Uncal compression of the right midbrain
B. Compression of the left midbrain
C. Diffuse axonal injury involving the right inter-
nal capsule
D. Spinal cord injury
E. Left-side Duret hemorrhages in the pons

Answer 93

B. Compression of the left midbrain

A mass lesion and uncal herniation often cause
an ipsilateral cranial nerve III palsy with a contralateral hemiparesis due to compression of the ipsilateral midbrain. The brainstem can continue to
be compressed against the contralateral incisura,
affecting the ipsilateral cranial nerve III and the
contralateral midbrain causing an ipsilateral hemiparesis. This is known as the Kernohan phenomenon, which is a false localizing sign.

Question 94

What is the most effective means of sterilization for
operating room procedures involving Creutzfeldt-
Jakob disease?
A. Boiling
B. Immersion in 1 N NaOH for 15 minutes
C. Ultraviolet radiation
D. Immersion in sodium hypochlorite
E. Steam autoclaving for 1 hour at 132°C

Answer 94

E. Steam autoclaving for 1 hour at 132°C

Creutzfeldt-Jakob disease is resistant to all routine sterilization/disinfection procedures commonly used. The two reported effective methods
for providing sterilization are steam autoclaving
for 1 hour at 132°C and immersion in 1 N NaOH for
1 hour. The other listed options are ineffective at
fully sterilizing for equipment contaminated with
Creutzfeldt-Jakob disease prions.

Question 95

What is the most common location for dural
arteriovenous fistulae to drain?
A. Superior sagittal sinus
B. Junction of the transverse and sigmoid sinus
C. Cavernous sinus
D. Inferior petrosal sinus
E. Junction of the sigmoid sinus and jugular vein

Answer 95

B. Junction of the transverse and sigmoid sinus

Question 96

With subthalamic nucleus deep brain stimulation,
the adverse effect of flushing and sweating follow-
ing surgery indicates current spread to what direc-
tion relative to the intended target?
A. Anterior
B. Posterior
C. Lateral
D. Medial
E. Anterolatera

Answer 96

A. Anterior

The hypothalamus is anterior to the subthalamic
nucleus (STN), and current spread to the hypothalamus causes flushing and sweating. (B) The medial
lemniscus is posterior to the STN, and stimulation
results in the adverse effect of paresthesia. (C) The
corticobulbar tract is lateral to the STN, and stimulation results in the adverse effect of dysarthria.
(D) The red nucleus is medial to the STN, and
stimulation results in the adverse effect of ataxia.
(E) The corticospinal tract is anterolateral to the
STN, and stimulation results in the adverse effect
of tonic contraction.

Question 97

What is a contraindication to performing an ante-
rior lumbar interbody fusion?
A. Unilateral pars defect
B. Bilateral pars defect
C. Grade 3 or 4 spondylolisthesis
D. Severe loss of disk space height
E. Grade 1 isthmic spondylolisthesis

Answer 97

C. Grade 3 or 4 spondylolisthesis

In high-grade spondylolisthesis, the nerve roots
are stretched. Increasing disk space height without first decompressing the nerve roots with some
realignment would place the patient at a high risk
for nerve root injury

Question 98

A 65-year-old woman presents with headache. She
describes scalp tenderness in the temporal region,
with her jaw being stiff when she chews. She also
describes chronic fatigue, muscle aches, and weight
loss. Headache treatment is started, and she is
scheduled for surgery. With what complication can
a delay in the treatment of her suspected diagnosis
be associated?
A. Blindness
B. Re-rupture
C. Contiguous intracranial spread
D. Herniation
E. Corneal abrasions

Answer 98

A. Blindness

The patient’s case is suggestive of temporal
(giant cell) arteritis. It is found in women over 50
years of age and is associated with polymyalgia
rheumatic. Involvement of the ophthalmic artery
can lead to blindness if the condition is untreated.
Diagnosis is by biopsy of the temporal artery and
elevated erythrocyte sedimentation rate. Steroid
treatment should begin immediately when the
diagnosis is suspected. (B) Aneurysm rupture is
associated with an acute, “thunderclap” headache,
although prodromal headaches can occur. (C) Contiguous spread of a periodontal abscess is rare, and usually is associated with dental procedures or
poor dentition. (D) Cerebral herniation from trauma
or a large brain tumor would manifest with signs
of increased intracranial pressure (nausea, vomiting, hemiparesis, and decreased mental status).
(E) Corneal abrasions can be the result of herpes
zoster involving the ophthalmic division of the trigeminal nerve.

Question 99

A 22-year-old man presents after a motorcycle
accident complaining of neck pain and lower
extremity paraplegia. He has a cervical burst frac-
ture. His exam demonstrates 0/5 strength in the
lower extremities. He has 4/5 strength in the bi-
ceps and wrist extensors bilaterally. He has 0/5
strength in the triceps, grip, and hand intrinsics.
What is the American Spinal Injury Association
(ASIA) motor score?
A. 8
B. 16
C. 42
D. 58
E. 92

Answer 99

B. 16

The American Spinal Injury Association (ASIA)
motor score is based on key muscles representing
root levels. There are 50 points available for testing in the upper extremities (25 right and 25 left)
and 50 points in the lower extremities (25 right
and 25 left). Key muscles include the biceps, wrist
extensors, flexor digitorum profundus, hand intrinsics, iliopsoas, quadriceps, tibialis anterior, extensor
hallucis longus, and gastrocnemius.

Question 100

What is the benign lesion seen in this intraopera-
tive image with a gross pearly white appearance
A. Epidermoid cyst
B. Dermoid cyst
C. Lipoma
D. Adamantinomatous craniopharyngioma

Answer 100

A. Epidermoid cyst

Epidermoid tumors are thin walled, with a characteristic smooth, pearly white appearance on gross
examination. (B) Dermoid cysts are thick walled,
with greasy pilosebaceous contents. (C) Lipomas
have a yellow, fatty gross appearance. (D) Adamantinomatous craniopharyngiomas are partly cystic
with white speckled keratin nodules.

Question 101

A patient presents with complaints of a herniated
disk that correlates with imaging. MRI demon-
strates a far lateral disk herniation at L4/L5. What
nerve root should be affected?
A. L4 traversing nerve root
B. L4 exiting nerve root
C. L5 traversing nerve root
D. L5 exiting nerve root

Answer 101

B. L4 exiting nerve root

Most L4/L5 disk herniations affect the traversing nerve root (L5 in this example). Far lateral
herniations affect the exiting nerve root (L4 in
this example).

Question 102

Isthmic spondylolisthesis is found in what group of
patients?
A. HLA-B27 histocompatability complex positive
individuals
B. Truck drivers
C. Rheumatoid arthritis patients
D. Gymnasts, football linemen, and weight lifters
E. Black people, diabetics, and women over 40
years old

Answer 102

D. Gymnasts, football linemen, and weight lifters

Isthmic spondylolisthesis is thought to have a
higher incidence in sports and activities that involve
repetitive hyperextension. (A) HLA-B27 positivity
is seen in ankylosing spondylitis. (C) Rheumatoid
arthritis causes atlantoaxial subluxation, subaxial
subluxation, and basilar invagination. (E) Being
black, having diabetes, and being a woman over
40 years of age are risk factors for degenerative
spondylolisthesis. The occurrence in women is
thought to be due to ligamentous laxity related to
hormonal changes.

Question 103

This image shows what type of intracranial lesion?
A. Arachnoid cyst
B. Epidermoid cyst
C. Dermoid cyst
D. Neurenteric cyst

Answer 103

B. Epidermoid cyst

Epidermoid cysts appear as well-defined, often
relatively round masses with thin, pearly white
walls. The cysts contain a dense, keratinous substance. (A) Arachnoid cysts are thin walled (often
translucent), and contain clear fluid similar to the
makeup of cerebrospinal fluid. (C) Dermoid cysts
(mature teratomas) are thick walled, and contain a
variety of mature tissues, including hair, sebaceous
glands, and skin. (E) Neurenteric cysts are thick
walled, and often have variable contents but typically contain a thick, creamy, mucin-like substance.

Question 104

A 70-year-old woman presents with large, enhanc-
ing frontoparietal mass suspicious for a glioblas-
toma. She is unable to work but is able to live at
home and care for some of her personal needs. She
requires considerable assistance and frequent med-
ical care. What is the estimated Karnofsky Scale
score?
A. 10
B. 30
C. 50
D. 70
E. 90

Answer 104

C. 50

The Karnofsky Performance Scale classifies
patients based on their functional impairments. The
lower the score, the worse the survival is for most
serious illnesses. Scores of 0 to 40 indicate that
patients are unable to care for themselves. Score of
50 to 70 indicate that patients are unable to work
but otherwise are able to live at home with varying
amounts of assistance needed. Scores of 80 to 100
indicate that patients are able to carry on normal
activities and work with no special care needed.

Question 105

Ankylosing spondylitis is associated with what
human leukocyte antigen?
A. HLA-DQA1
B. HLA-DRB1
C. HLA-B27
D. HLA-DR2
E. HLA-B47

Answer 105

C. HLA-B27

(A) HLA-DQA1 is associated with diabetes type 1
and celiac disease. (B) HLA-DRB1 is associated
with rheumatoid arthritis and multiple sclerosis.
(D) HLA-DR2 is associated with lupus. (E) HLA-B47
is associated with 21-hydroxylase deficiency

Question 106

Current spread in what direction during sub-
thalamic nucleus deep brain stimulation will cause
double vision and pupillary constriction?
A. Anterior
B. Posterior
C. Lateral
D. Medial
E. Inferomedial

Answer 106

E. Inferomedial

The nuclei of cranial nerves III and IV are inferomedial to the STN. Current spread to this area
causes diplopia and miosis. (A) The hypothalamus
is anterior to the subthalamic nucleus (STN), and
stimulation results in the adverse effect of flushing and sweating. (B) The medial lemniscus is posterior to the STN, and stimulation results in the
adverse effect of paresthesia. (C) The corticobulbar tract is lateral to the STN, and stimulation
results in the adverse effect of dysarthria. (D) The
red nucleus is medial to the STN, and stimulation
results in the adverse effect of ataxia

Question 107

During a carotid endarterectomy, the internal
carotid artery (ICA) is identified coursing posterior
to the external carotid artery (ECA). What land-
mark is used to differentiate the external from the
internal carotid artery during surgery?
A. Lingual artery arising from the ECA
B. Superior thyroid artery arising from the ECA
C. Ascending pharyngeal artery arising from the
ECA
D. Facial vein coursing over the ECA
E. Ascending pharyngeal artery arising from the
ICA

Answer 107

B. Superior thyroid artery arising from the ECA

The superior thyroid artery is the first branch
arising from the external carotid artery. The
remaining branches (in ascending order) are the ascending pharyngeal, lingual, facial, occipital,
posterior auricular, and superficial temporal and
internal maxillary arteries. (E) The internal carotid
artery has no extracranial branches.

Question 108

Prior to cross-sectional imaging, a named point was
used to identify the fourth ventricle and deter-
mine if any midline shift was present. Where is
this point located?
A. Where the septal and thalamostriate veins
converge
B. At the arterial branch from the inferior extent
(caudal loop) of the tonsillomedullary segment
of the posterior inferior cerebellar artery
C. Where the posterior choroidal artery enters
the velum interpositum
D. At the arterial branch from the superior extent
(cranial loop) of the telovelotonsillar segment
of the posterior inferior cerebellar artery
E. Where the anterior choroidal artery enters the
choroidal fissure of the lateral ventricle

Answer 108

D. At the arterial branch from the superior extent
(cranial loop) of the telovelotonsillar segment
of the posterior inferior cerebellar artery

The choroid point is located at the point where
the choroidal artery emerges from the telovelotonsillar segment of the posterior inferior cerebellar
artery. (A) The venous angle occurs at the convergence of the septal and thalamostriate vein at the
foramen of Monro. These two veins join to form
the internal cerebral vein. (B) The copular point is
where the inferior vermian artery forms the inferior inflection point of the posterior inferior cerebellar artery on cerebral angiogram. (E) The plexal
point is where the anterior choroidal artery enters
the lateral ventricle and can be seen on cerebral
angiogram

Question 109

What recess is indicated by the arrow in this image?
A. Opticocarotid cistern
B. Carotico-oculomotor cistern
C. Interpeduncular cistern
D. Lamina terminalis
E. Cerebellopontine angle

Answer 109

A. Opticocarotid cistern

The image accompanying the question illustrates
a left-sided approach that may be seen with a pterional craniotomy. The carotid artery is seen lateral to the optic nerve. The internal carotid artery
bifurcation is seen as the anterior cerebral artery
A1 segment crosses the optic nerve in the five
o’clock position of the image. The middle cerebral
artery M1 segment is found at the seven o’clock
position. The arrow points to the opticocarotid
recess. (B) The carotico-oculomotor membrane is
bound superiorly by the superior dural ring and
inferiorly by the inferior dural ring and is intimately related to cranial nerve III.

Question 110

In the adult patient, subdural effusions are associ-
ated with what entity?
A. Chronic subdural hematomas
B. Tuberculosis
C. Syphilis
D. Haemophilus influenzae meningitis
E. Skull fractures

Answer 110

D. Haemophilus influenzae meningitis

Subdural effusions are rare complications of bacterial meningitis (most commonly caused by Haemophilus influenzae). Chronic subdural hematomas
are referred to as hygromas.

Question 111

A patient is referred to the neurosurgical clinic for
a dural arteriovenous fistula (dAVF). An angiogram
shows anterograde drainage into a venous sinus
with retrograde flow into subarachnoid veins. What
is the Borden classification for this dAVF?
A. 1
B. 2
C. 3
D. 4
E. 5

Answer 111

B. 2

The Borden classification system grades dAVFs 1
to 3. In addition, each type is subclassified further
into type A (single-hole fistula) or B (multiple-hole
fistula). Cortical venous reflux (types 2 and 3) is
the most important prognostic factor for dAVFs
regarding their hemorrhage and nonhemorrhage
neurologic deficit rates. A type 2 dAVF has drainage into normal veins/sinuses, with high pressure
causing retrograde flow into normal subarachnoid
veins (equivalent to a 2B and 2A+B dAVF in the
Cognard classification). (A) A Borden type 1 dAVF
has normal anterograde flow through the fistula
(equivalent to a Cognard type 1 and 2A dAVF).
(C) A Borden type 3 dAVF has direct drainage into
subarachnoid veins or an isolated segment of a
sinus (from thrombosis on either side of the fistula) and is equivalent to a Cognard type 3, 4, or 5
dAVF. (D, E) The Borden classification system only
grades dAVFs as 1 to 3.

Question 112

What structure impedes the caudal exposure of the
thoracic spine during a transthoracic approach?
A. Vena cava
B. Aorta
C. Diaphragm
D. Liver
E. Twelfth rib

Answer 112

C. Diaphragm

The attachment of the diaphragm at the T12 to
L1 levels increases the difficulty of transthoracic
access to the thoracic spine around the T10 level
and inferiorly.

Question 113

After a proximal shunt revision surgery, a patient
is unable to void and requires straight catheteriza-
tion. What is the most appropriate next step in
treating this patient’s condition?
A. Obtain a urology consultation for possible
bladder injury.
B. Administer bethanechol.
C. Administer diazepam
D. Administer oxybutynin.
E. Administer morphine.

Answer 113

B. Administer bethanechol.

Postoperative urinary retention (POUR) due to
anesthesia is a common phenomenon. Bethanechol is a parasympathomimetic agent that facilitates detrusor contraction and relaxes the bladder
sphincter. (A) The patient’s surgery was for a proximal (ventricular catheter) shunt revision only.
The distal shunt catheter was not touched, and the
abdomen was not entered; therefore, it is unlikely
the bladder was injured. (C) Diazepam is an anxiolytic agent that binds to benzodiazepine receptors.
It acts as a muscle relaxant. Studies show that diazepam is not effective in treating POUR. (D) Oxybutynin antagonizes acetylcholine at muscarinic
receptors and relaxes bladder smooth muscles.
Due to its anticholinergic affect, it inhibits involuntary detrusor muscle contractions and is used to
treat overactive bladder and not urinary retention.
(E) Morphine is an opioid narcotic and only will
make the urinary retention worse

Question 114

Occlusion of a dAVF is most effective with what
minimally invasive method?
A. Transvenous coil embolization
B. Transarterial embolization with Onyx glue
C. Minimally invasive keyhole endoscopic micro-
surgical clip ligation of feeding arteries
D. Stereotactic radiosurgery

Answer 114

A. Transvenous coil embolization

Transvenous coil embolization to occlude the
proximal draining veins just distal to the point of
the fistula is the most effective endovascular technique in treating a dAVF. (B) Transarterial embolization with Onyx glue is an option in treating a
dAVF, but using a liquid embolic agent can risk
occluding perforating vessels. (C) Direct surgical
clip ligation should be done on the draining veins
and not the arteries in a dAVF. (D) Stereotactic
radiosurgery is an option for treating a dAVF, but
it can require multiple treatments.

Question 115

During an endonasal transsphenoidal approach,
what structure limits the working space and ma-
neuverability of the instruments?
A. Inferior turbinate
B. Middle turbinate
C. Superior turbinate
D. Anterior nasal septum

Answer 115

B. Middle turbinate

The middle turbinate provides the most obstruction in the working space during the endonasal
transsphenoidal approach. The middle turbinate on
one side can be removed, whereas the one in the
opposite nostril can be lateralized for more working space. (D) The posterior portion of the nasal
septum, not the anterior portion, often is removed
to create an optimal working space.

Question 116

Patients flying soon after major intracranial surgery
may be theoretically at risk for what complication?
A. Blindness
B. Wound infection
C. Pneumonia
D. Tension pneumocephalus
E. Spontaneous hemorrhage

Answer 116

D. Tension pneumocephalus

In theory, because of pressure changes and the
decreased atmospheric pressure maintained within
the pressurized cabins of commercial aircraft (about
0.75 atm), the brain following craniotomy may be
at an increased risk for tension pneumocephalus.
Patients also may be at an increased risk for developing deep venous thromboses due to the prolonged immobility associated with air travel.

Question 117

What is the most common site of ulnar nerve com-
pression around the elbow?
A. Arcade of Struthers
B. Cubital tunnel
C. Medial epicondyle
D. Medial intramuscular septum
E. Deep flexor aponeurosis

Answer 117

B. Cubital tunnel

The cubital tunnel is the most common site of
ulnar nerve compression. The second most common
site is the Guyon canal at the wrist. Decompression
of the arcade of Struthers (not the Struthers ligament) occurs when freeing the ulnar nerve during
a cubital tunnel release.

Question 118

Although not always conclusive, what imaging
sequence is most helpful in differentiating a cere-
bral abscess from a tumor?
A. CT with contrast
B. MR T1 with contrast
C. MR FLAIR
D. Diffusion-weighted imaging
E. MR angiography

Answer 118

D. Diffusion-weighted imaging

Both CT and MR with contrast sequences are
helpful to view abscesses with high sensitivity,
but it can be difficult to differentiate between an
abscess and a tumor. Classically, abscesses show
diffusion restriction (dark on apparent diffusion
coefficient [ADC] sequences), suggesting viscous
fluid, whereas tumors most often will be dark on
diffusion-weighted imaging (DWI) sequences. Positive diffusion restriction is seen more often with
pyogenic abscesses, and becomes less reliable with
fungal or tuberculosis abscesses.

Question 119

What components constitute the system for indo-
cyanine green video angiography?
A. Incandescent tungsten-halogen light source
projecting light through the collector lens and
into the substage condenser
B. Mercury vapor arc lamp with a mono-
chromatic light source expanded in the near-
ultraviolet
C. Argon ion emission at 488 to 514 nm used in
confocal source emission
D. Near-infrared light source with an optical filter to block ambient and excitation light
E. Electronic flash 5500 K illumination to capture
specimens with high-speed daylight trans-
parency film

Answer 119

D. Near-infrared light source with an optical filter to block ambient and excitation light

(A) This describes the modern microscope. (B) Arc
lamps often are used for black-and-white photomicrography. (C) This describes true confocal scanning microscopy. (E) This describes high-speed specimen image capturing.

Question 120

A bilateral thalamotomy is contraindicated due to
the possibility of what side effects?
A. Hemiparesis and homonymous hemianopsia
B. Dysarthria and cognitive impairment
C. Myosis and anhydrosis
D. Quadriparesis and respiratory depression
E. Hemiparesis and bladder dysfunction

Answer 120

B. Dysarthria and cognitive impairment

Dysarthria and cognitive impairment are complications of bilateral thalamotomy. (A) Hemiparesis
and homonymous hemianopsia are complications
of pallidotomy due to injury to the internal capsule
and optic tract. (C) Horner syndrome, characterized by myosis and anhydrosis, is a complication
of sympathectomy. (D) Quadriparesis and respiratory depression (Ondine curse) are associated with
bilateral cordotomy complications. (E) Hemiparesis
and bladder dysfunction are complications of midline myelotomy in the treatment of pelvic pain due
to cancer.

Question 121

What are the Surgical Care Improvement Project
(SCIP) prophylactic antibiotic guidelines?
A. All surgical patients must receive cefazolin
prior to the skin incision.
B. Prophylactic antibiotics must be received
within 1 hour prior to the surgical incision.
C. Prophylactic antibiotics should be continued
for 24 hours after the surgery end time.
D. Prophylactic antibiotics should be continued
for at least 48 hours after the surgery end
time.

Answer 121

B. Prophylactic antibiotics must be received
within 1 hour prior to the surgical incision.

1 hour prior to the surgical incision
(A) There are specific algorithms for prophylactic
antibiotic selection for surgical patients depending
on the surgical site and infection risks; therefore,
not every surgical patient should receive cefazolin
as the prophylactic antibiotic. (C, D) Prophylactic
antibiotics are discontinued within 24 hours after
the surgery end time.

Question 122

What procedure is best at relieving the symptoms
associated with a traumatic brachial plexus nerve
root avulsion?
A. Cordotomy
B. Midline myelotomy
C. Dorsal root entry zone lesioning
D. Cingulotomy
E. Rhizotomy

Answer 122

C. Dorsal root entry zone lesioning

Dorsal root entry zone lesioning is most beneficial for symptom relief with nerve avulsion pain
such as that of the brachial plexus or in transitional
zone pain following a spinal cord injury. The procedure should be reserved for patients who have
shown no evidence of functional recovery of the
nerve. (A) Cordotomies are used for cancer-related
pain of the upper extremity, chest, or peritoneum.
(B) Midline myelotomies are used for relieving
midline visceral cancer pain in the pelvic and rectal regions. (D) Anterior cingulotomies are used for
chronic, noncancer pain. (E) Rhizotomies destroy
nerve roots and are used for spastic cerebral palsy.
Selective dorsal rhizotomies are performed in the
lower spinal cord and are best for diplegic spasticity. The procedures are used primarily in treating
children with cerebral palsy with lower extremity
spasticity who have borderline ambulatory abilities.

Question 123

Superior hypophyseal artery aneurysms usually
have what orientation compared to the parent
vessel?
A. Oriented superolaterally
B. Oriented posterolaterally
C. Oriented inferolaterally
D. Oriented inferomedially
E. Oriented posteromedially

Answer 123

C. Oriented inferolaterally

Question 124

How does melanoma in the central nervous sys-
tem respond to radiation?
A. Melanoma is entirely radiation insensitive and
should not be treated by radiation.
B. Melanoma is mostly radiation insensitive, but
radiation may be somewhat effective
C. Melanoma is mostly radiation sensitive, and
radiation typically may be effective.
D. Melanoma is entirely radiation sensitive and
should be treated primarily by radiation.

Answer 124

B. Melanoma is mostly radiation insensitive, but
radiation may be somewhat effective

Question 125

A 58-year-old woman underwent an uneventful
single-level anterior cervical diskectomy and fusion
(ACDF). Six months later, she presented with a low-
grade fever, dysphagia, anorexia, and neck pain.
The symptoms had been ongoing for a month. MRI
showed osteomyelitis at the surgical site. What is
the most appropriate diagnostic test to find the
source of infection?
A. Panorex imaging to look for dental abscesses
B. Echocardiogram
C. Blood cultures
D. Upper gastrointestinal imaging
E. Nuclear bone scan

Answer 125

D. Upper gastrointestinal imaging

Esophageal perforation can present in an immediate or delayed fashion after anterior cervical
diskectomy and fusion surgery. Occasionally, if the
plating is high profile or if the screws are proud,
they can irritate and erode through the esophagus
over time, especially when the patient is swallowing. Imaging should include an esophagoscopy,
barium swallow study, or esophagogastroduodenoscopy. (A) Dental abscesses are unlikely to be the
source of the infection at the surgical site. (B) An
echocardiogram can assess the presence of endocarditis from vegetations on the cardiac valves.
Although this is a possible explanation for the
patient’s infection, a cardiac source is unlikely unless esophageal perforation has been completely
ruled out. (C) Blood cultures help determine if
the patient has a systemic infection/sepsis but are
not helpful in determining the direct source. (E) A
nuclear bone scan only confirms the MRI finding of
osteomyelitis and is not helpful in elucidating the
infectious source.

Question 126

What bone product is primarily an osteoinductive
agent?
A. Demineralized bone matrix
B. Bone morphogenic protein
C. Cadaveric fibular strut
D. Tricalcium phosphate
E. Hydroxyapatite

Answer 126

B. Bone morphogenic protein

Optimal success of a bone growth provides structural support, fills voids, and improves healing
through osteoconductive (matrix for bone growth),
osteoinductive (growth factors to encourage cells
to differentiate into osteoblastic cells), and osteogenic (directly transplanted osteoblasts/periosteal
cells) properties. Autograft is the gold standard to
induce bone growth. Bone morphogenic protein
is primarily an osteogenic material. Cortical bone
grafts are less biologically active than cancellous
bone grafts, but they provide more structural
support and may provide an osteoconductive scaffold. Demineralized bone matrix is prepared from
cadaveric bone, and although it has some low osteoinductive potential, demineralized bone matrix
is considered mainly an osteoconductive agent.
(D, E) Tricalcium phosphate and hydroxyapatite
are components of bone and bone growth and are
considered osteoconductive

Question 127

What size must an aneurysm be to be considered
giant?
A. 0.7 cm
B. 1.0 cm
C. 1.5 cm
D. 2.5 cm
E. 4.0 cm

Answer 127

D. 2.5 cm

In general, giant aneurysms are thought to have
a lower annual rate of rupture compared to nongiant aneurysms.

Question 128

Ophthalmic artery aneurysms usually have what
orientation and origin compared with the parent
vessel?
A. Oriented medially and arising from the poste-
rior wall
B. Oriented superiorly and arising from the ante-
rior wall
C. Oriented anteriorly and arising from the pos-
terior wall
D. Oriented superiorly and arising from the
superior wall
E. Oriented anteriorly and arising from the ante-
rior wall

Answer 128

D. Oriented superiorly and arising from the
superior wall

Ophthalmic artery aneurysms tend to point toward the optic nerve

Question 129

Anterior communicating artery (ACOM) aneurysms
usually have what orientation and origin com-
pared with the parent vessel?
A. Directed laterally and arising from the branch
point of the dominant A1 segment and the
ACOM
B. Directed laterally and arising from the non-
dominant A2 segment
C. Directed laterally and arising from the domi-
nant A2 segment
D. Directed contralaterally and arising from the
branch point of the nondominant A1 segment
and the ACOM
E. Directed contralaterally and arising from the branch point of the dominant A1 segment and the ACOM

Answer 129

E. Directed contralaterally and arising from the branch point of the dominant A1 segment and the ACOM

Question 130

What is the most common location for the “pearly”
tumor shown in this image?
A. As part of the dural along the cerebral
convexities
B. Cerebellopontine angle
C. Thalamus
D. Extra-calvarial
E. Pineal gland

Answer 130

B. Cerebellopontine angle

Epidermoid cysts occur in the cerebellopontine
angle in 40 to 50% of cases and are the third most
common cerebellopontine angle tumor. They also
are found in the fourth ventricle and sellar region.
Less common locations are the cerebral hemispheres, brainstem, and extradural spine/skull.

Question 131

A man underwent a long-segment spine surgery
while positioned supine with the lower extremity
externally rotated at the hip with the knee flexed.
Iatrogenic injury to what nerve is most likely to
result from this operative position?
A. Common peroneal nerve
B. Deep peroneal nerve
C. Superficial peroneal nerve
D. Obturator nerve
E. Lateral femoral cutaneous nerve

Answer 131

A. Common peroneal nerve

Iatrogenic common peroneal nerve injuries can
result from improperly placing the patient in the
supine position. These injuries result in foot drop
and weakness with foot eversion. To avoid this, pillows are placed under the knee with the leg midline and not externally rotated. (B) Deep peroneal
nerve injuries result in vague pain and dysesthesia
over the dorsum of the foot. (C) Superficial peroneal nerve injuries result in pain and numbness
over the lateral malleolus and occasionally in the
lateral leg. (D) The obturator nerve is prone to
injury during obstetric and gynecologic procedures.
(E) Injury to the lateral femoral cutaneous nerve
results in “meralgia paresthetica.”

Question 132

A 50-year-old woman presents to the hospital
after a new onset of seizures. She describes head-
ache and poor vision. Her family notes that her
memory has been worsening, and she is becoming
more confused. Neurologic exam reveals a loss
of smell on the left side. Ophthalmologic exam
reveals a pale left optic disk. The right optic disk is
congested and edematous. What is her most likely
diagnosis?
A. Pituitary adenoma
B. Posterior reversible encephalopathy syndrome
C. Olfactory groove meningioma
D. Brainstem cavernoma
E. Central pontine myelinolysis

Answer 132

C. Olfactory groove meningioma

The patient has Foster-Kennedy syndrome with
ipsilateral anosmia, ipsilateral optic nerve atrophy,
and contralateral papilledema. This classically is
seen with olfactory groove meningiomas. Neurologic localization would place this lesion at the
inferior surface of the left inferior frontal lobe.

Question 133

The roof of the third ventricle is composed of how
many layers?
A. Two
B. Three
C. Four
D. Five
E. Six

Answer 133

D. Five

The roof of the third ventricle contains five layers; from rostral to caudal, they are the body of the
fornix, the superior layer of the tela chorioidea, the
velum interpositum (vascular layer), the inferior
layer of the tela chorioidea, and the choroid plexus.

Question 134

When harvesting the sural nerve, what structure
accompanies the nerve as it courses lateral to the
Achilles tendon?
A. Superficial peroneal nerve
B. Great saphenous vein
C. Small saphenous vein
D. Posterior tibial artery
E. Posterior tibial vein

Answer 134

C. Small saphenous vein

The small saphenous vein originates in the dorsolateral foot and courses around the lateral foot
and then between the heads of the gastrocnemii to
drain into the popliteal vein in the popliteal fossa.

Question 135

What is the primary disadvantage of approaching
a pineal region tumor using an infratentorial supra-
cerebellar approach?
A. Difficulty may be encountered navigating
around the deep venous system.
B. Morbidity may be associated with positioning
C. Visual deficits are likely.
D. Seizures may be induced.
E. Disconnection syndrome may occur.

Answer 135

B. Morbidity may be associated with positioning

The major disadvantage of the infratentorial supracerebellar approach concerns positioning difficulties and morbidity. This approach often involves
a patient in the sitting position (or a variation
thereof) and utilizes gravity to allow the cerebellum to fall away from the surgical corridor. The
sitting position is notorious for being associated
with an elevated risk for developing an air embolism and with surgeon discomfort and fatigue.
(A) The deep venous system typically is superior to
pineal region tumors. (C) Visual deficits occur with
occipital transtentorial procedures. (D) Seizures
are more common with transcortical approaches.
(E) Disconnection syndromes are more prevalent
with interhemispheric approaches that are more
posteriorly based.

Question 136

What are the current recommendations (level 2
evidence) for use of prophylactic anticonvulsants
in the setting of a traumatic brain injury?
A. The use of prophylactic anticonvulsants is
recommended for 30 days following injury to
decrease the risk of posttraumatic seizures.
B. Prophylactic anticonvulsants have not been
shown to decrease the risk of posttraumatic
seizures.
C. Prophylactic anticonvulsant use for 6 months
following injury has been shown to decrease
the incidence of late posttraumatic seizures.
D. Prophylactic anticonvulsants are indicated to
decrease the incidence of early posttraumatic
seizures
E. Prophylactic anticonvulsants are indicated to
decrease the incidence of late posttraumatic
seizures occurring more than 6 months fol-
lowing injury.

Answer 136

D. Prophylactic anticonvulsants are indicated to
decrease the incidence of early posttraumatic
seizures

In the setting of a traumatic brain injury, anticonvulsants typically are used for no more than 1
week as early post-traumatic seizure prophylaxis.

Question 137

A 36-year-old woman is diagnosed with a rup-
tured, wide neck posterior communicating aneu-
rysm with a fetal posterior cerebral artery. After
an uneventful clipping of the aneurysm, she wakes
up with contralateral weakness and numbness and
a homonymous hemianopsia. What event likely
caused the postoperative symptoms?
A. Incorporation of the posterior communicating
artery into the aneurysm clip
B. Prolonged placement of temporary clips
C. Thromboembolic event
D. Vasospasm
E. Incorporation of the anterior choroidal artery into the aneurysm clip

Answer 137

E. Incorporation of the anterior choroidal artery into the aneurysm clip

When clipping a posterior communicating artery
aneurysm, it is important to identify the anterior
choroidal artery as it is in close proximity to the
posterior communicating artery and can be incorporated into an aneurysm clip. The anterior choroidal artery supplies the blood to the posterior
limb of the internal capsule and can lead to the
classic “triple H” syndrome consisting of hemiparesis, hemisensory loss, and a homonymous hemianopsia. If the posterior cerebral artery is fetal,
incorporation into an aneurysm clip may cause an
occipital stroke and consequential visual loss.

Question 138

What are the resection limits of the dominant and
nondominant temporal lobes, respectively, as mea-
sured along the middle temporal gyrus from the
temporal pole in an anterior-posterior direction?
A. 2 to 3 cm; 6 to 7 cm
B. 4 to 5 cm; 4 to 5 cm
C. 6 to 7 cm; 8 to 9 cm
D. 4 to 5 cm; 6 to 7 cm
E. 3 to 4 cm; 8 to 9 cm

Answer 138

D. 4 to 5 cm; 6 to 7 cm

Some neurosurgical centers spare the superior
temporal gyrus during resections, if possible. A
resection of more than 5 cm in the dominant temporal lobe risks injuries to the speech centers. A
resection of more than 7 cm in the nondominant
temporal lobe risks a partial quadrantanopsia,
whereas an 8- to 9-cm resection leads to a complete quadrantanopsia.

Question 139

A patient with a baclofen pump presents with a
high-grade fever, hyperreflexia, and seizures. What
is the underlying cause of this patient’s symptoms?
A. Infected hardware
B. Baclofen toxicity
C. Meningitis
D. Baclofen withdrawal

Answer 139

D. Baclofen withdrawal

Baclofen is used to treat spasticity. Withdrawal
can lead to hyperthermia, hyperreflexia, spasticity, seizures, and delirium. Immediate treatment
includes baclofen administration. (A, C) Unless the
patient has constitutional signs of infection, these
symptoms are more similar to neuroleptic malignant syndrome-like findings associated with baclofen withdrawal. (B) Baclofen toxicity causes
hyporeflexia, bradycardia, hypothermia, and even
respiratory arrest.

Question 140

Scheuermann disease is defined as:
A. Nontraumatic anterior wedging of at least 5 degrees in at least three adjacent thoracic ver-tebral bodies
B. Hypermobility of the craniovertebral junction
C. Congenital fusion of two or more cervical
vertebrae
D. Nontraumatic subluxation of the atlantoaxial
joint caused by inflammation or infection
E. Compression of the esophagus and dysphagia
resulting from a cervical osteophyte

Answer 140

A. Nontraumatic anterior wedging of at least 5 degrees in at least three adjacent thoracic ver-tebral bodies

Scheuermann disease is due to an uneven growth
of the vertebrae in the sagittal plane resulting in
a kyphotic spine. (C) Klippel-Feil syndrome is
described as the congenital fusion of two or more
cervical vertebrae. (D) Grisel syndrome is described
as the nontraumatic subluxation of the atlantoaxial joint caused by inflammation or infection.
(E) Forestier disease is defined as the compression
of the esophagus and dysphagia resulting from a
cervical osteophyte.