neurosurgery 2

Question 1

QUESTIONS 1-4
Scenario: A 15-month-old girl was brought to the emergency department for lethargy, nausea, and vomiting and was found to have aqueductal stenosis on brain MRI.

Q : What is the best treatment strategy for this patient?
A. Observation
B. Placement of a subgaleal shunt
C. Placement of a ventriculoperitoneal shunt followed
by endoscopic third ventriculostomy if shunting fails
D. Endoscopic third ventriculostomy
E. Endoscopic third ventriculostomy followed by septostomy

Answer 1

D. Endoscopic third ventriculostomy

Question 2

All of the following are advantages of endoscopic third
ventriculostomy (ETV) over shunting EXCEPT?

A. Lower rate of subdural hematoma formation with ETV
B. Higher rate of craniosynostosis with ETV
C. Lower infection rate with ETV
D. Physiologic CSF diversion with ETV
E. Higher chance of overdrainage with shunt placement

Answer 2

B. Higher rate of craniosynostosis with ETV

Question 3

All of the following are true about preoperative planning
for ETV EXCEPT?

A. It is relatively straightforward to accurately determine the future function of the subarachnoid pathways and patency of the ETV as long as a high resolution MR cisternogram is obtained preoperatively that identifies the level of the block
B. MRI can accurately delineate the anatomy of the foramen
of Monro, third ventricle, and massa intermedia
C. The position of the basilar artery and the thickness
of the third ventricular floor can be verified on most
preoperative MRIs
D. A prior history of CSF infection may decrease the
success rate of ETV
E. A prior history of a shunt is not an absolute contraindication
for ETV

Answer 3

A. It is relatively straightforward to accurately determine the future function of the subarachnoid pathways and patency of the ETV as long as a high resolution MR cisternogram is obtained preoperatively that identifies the level of the block

Question 4

What is the optimal site for fenestrating the floor of the
third ventricle during ETV?

A. Posterior to the mammillary bodies
B. Anterior to the infundibular recess, posterior to the
prechiasmatic space
C. In the most translucent area of the floor of the third
ventricle
D. Anterior to the mammillary bodies, posterior to the
infundibular recess
E. Anterior to the pulsations of the basilar artery

Answer 4

D. Anterior to the mammillary bodies, posterior to the
infundibular recess

ETV is a commonly performed procedure
for patients with aqueductal stenosis (AS). Although
there is some controversy about the age at which this
procedure should first be employed, results indicate high success rates for properly selected patients. Complications of shunting may include slit ventricle syndrome, intracranial hypotension, subdural hematomas, craniosynostosis, microcephaly, and overdrainage, which are typically not noted after endoscopy. The precise location to fenestrate the floor of the third ventricle may vary on a case-by-case basis, but perforating the floor anterior to the mamillary bodies and posterior to the infundibulum seems to a popular approach. Performing a septostomy in conjunction to a third ventriculostomy does not improve results in patients with AS, as the obstruction is downstream to the foramen of Monro. A patient with scarring or a cyst obstructing one foramen of Monro would likely benefit from this ancillary procedure. Predicting the success rate of ETV by preoperative imaging studies has proven to be very difficult, although identifying relevant anatomy (thickness of the floor of the third ventricle, location of basilar artery) to help guide the operation has proven to be effective

Question 5

The borders of the lateral recess include all of the following EXCEPT?

A. Pedicle
B. Superior articular facet
C. Inferior articular facet
D. Vertebral body
E. Spinal canal/thecal sac

Answer 5

C. Inferior articular facet

Question 6

The underlying cause of lateral recess stenosis is osteophyte
formation originating from what structure?

A. Inferior articular process
B. Pedicle
C. Superior articular process
D. Ligamentum flavum hypertrophy
E. Vertebral body

Answer 6

C. Superior articular process

Question 7

Although quite similar to the symptoms of radiculopathy secondary to discogenic disease, lateral recess stenosis can be differentiated from discogenic disease by which of the following?

A. Pain in the lateral recess syndrome is exacerbated by walking or standing
B. Failure of coughing or sneezing to aggravate pain in discogenic disease
C. Positive straight leg raising in lateral recess syndrome
D. Pain in lateral recess syndrome is relieved by postures accentuating lumbar lordosis
E. There is a slightly higher incidence of bladder incontinence with lateral recess stenosis

Answer 7

A. Pain in the lateral recess syndrome is exacerbated by walking or standing

Question 8

What is the best surgical strategy for patients with lateral
recess stenosis?
A. Laminectomy
B. Laminectomy with resection of the medial third of the
hypertrophied facet (medial facetectomy)
C. Microdiscectomy
D. Laminectomy and fusion
E. None of the above

Answer 8

B. Laminectomy with resection of the medial third of the hypertrophied facet (medial facetectomy)

Compression of nerve roots in the
lateral recess (lateral recess syndrome) can occur between a hypertrophied superior articular facet (dorsally), the pedicle (laterally), and the inferior vertebral body (ventrally). Medially, the lateral recess opens toward the spinal canal/thecal sac. The characteristic feature of lateral recess syndrome is that of radicular symptoms that occur mainly when the patient is walking or standing and are relieved by sitting, squatting forward, lying on either side, and/or postures that accentuate lumbar kyphosis. This is opposite to what is seen with patients harboring discogenic disease, who are uncomfortable while sitting. With the lateral recess syndrome, adequate decompression involves laminectomy with resection of the medial third of the hypertrophied facet (medial facetectomy), which is usually the superior articular process

Question 9

QUESTIONS 9-14
Directions: Match each of the following procedures with the potential complication using each answer once, more than once, or not at all.
A. Cordotomy
B. Periaqueductal gray stimulation
C. Percutaneous trigeminal electrocautery
D. Sympathectomy
E. Bilateral thalamotomy
F. Pallidotomy
G. Commisural myelotomy

Q : Dysarthria and cognitive decline

Question 10

Directions: Match each of the following procedures with the potential complication using each answer once, more than once, or not at all.
A. Cordotomy
B. Periaqueductal gray stimulation
C. Percutaneous trigeminal electrocautery
D. Sympathectomy
E. Bilateral thalamotomy
F. Pallidotomy
G. Commisural myelotomy

Q : “Ondine’s curse”

Answer 10

A. Cordotomy

Question 11

Directions: Match each of the following procedures with the potential complication using each answer once, more than once, or not at all.

A. Cordotomy
B. Periaqueductal gray stimulation
C. Percutaneous trigeminal electrocautery
D. Sympathectomy
E. Bilateral thalamotomy
F. Pallidotomy
G. Commisural myelotomy

Q : Eye movement disorder, pupillary dilation, feeling of fear

Answer 11

B. Periaqueductal gray stimulation

Question 12

Directions: Match each of the following procedures with the potential complication using each answer once, more than once, or not at all.

A. Cordotomy
B. Periaqueductal gray stimulation
C. Percutaneous trigeminal electrocautery
D. Sympathectomy
E. Bilateral thalamotomy
F. Pallidotomy
G. Commisural myelotomy

Q : Horner’s syndrome

Answer 12

D. Sympathectomy

Question 13

Directions: Match each of the following procedures with the potential complication using each answer once, more than once, or not at all.

A. Cordotomy
B. Periaqueductal gray stimulation
C. Percutaneous trigeminal electrocautery
D. Sympathectomy
E. Bilateral thalamotomy
F. Pallidotomy
G. Commisural myelotomy

Q : Anesthesia dolorosa

Answer 13

C. Percutaneous trigeminal electrocautery

Question 14

Directions: Match each of the following procedures with the potential complication using each answer once, more than once, or not at all.

A. Cordotomy
B. Periaqueductal gray stimulation
C. Percutaneous trigeminal electrocautery
D. Sympathectomy
E. Bilateral thalamotomy
F. Pallidotomy
G. Commisural myelotomy

Q : Leg weakness, dysesthesias, bladder dysfunction

Answer 14

G. Commisural myelotomy

Question 15

Directions: Match each of the following procedures with the potential complication using each answer once, more than once, or not at all.

A. Cordotomy
B. Periaqueductal gray stimulation
C. Percutaneous trigeminal electrocautery
D. Sympathectomy
E. Bilateral thalamotomy
F. Pallidotomy
G. Commisural myelotomy

Q : Hemiparesis, homonymous hemianopia

Answer 15

F. Pallidotomy

Direct sectioning of the spinothalamic tract (cordotomy) is very effective for
unilateral pain below the upper chest region, however, it is associated with many complications and is usually performed only in terminal patients. Complications of cordotomy include hemiparesis, respiratory depression (Ondine’s curse with bilateral procedures), and dysesthesias. Midline myelotomies can also be performed to interrupt the decussating fibers of the spinothalamic tract. This can be quite effective in the treatment of chronic pelvic pain secondary to cancer but is associated with leg weakness, dysesthesias, and bladder dysfunction. Chronic deep brain stimulation of the VPL and VPM nuclei of the thalamus as well as the periaqueductal gray (PAG) has been performed in the treatment of thalamic pain states, postherpetic neuralgia, and causalgia. Stimulation of the PAG has been associated with eye movement disorders, pupillary dilation, and the feeling of fear. Complications of pallidotomy include injury to the adjacent internal capsule (hemiparesis) and optic tract (homonymous hemianopsia), while complications of bilateral thalamotomy include speech problems and congnitive decline. Horner’s syndrome, pneumothorax, intercostal neuralgias, and spinal cord injury can occur after sympathectomy, while anesthesia dolorosa has been reported to occur after percutaneous trigeminal electrocautery

Question 16

tAll of the following are established procedures for the

treatment of trigeminal neuralgia EXCEPT?
A. Glycerol rhizolysis
B. Balloon decompression
C. Radiofrequency thermocoagulation
D. Microvascular decompression

E. Peripheral alcohol injecion

Answer 16

B. Balloon decompression

Peripheral alcohol injection, glycerol rhizolysis, radiofrequency thermocoagulation, and microvascular decompression are all established procedures for the treatment of trigeminal neuralgia. Peripheral balloon compression instead of decompression is a modification of the observation that open surgical decompression of the ganglion could lead
to significant pain relief in trigeminal neuralgia

Question 17

QUESTIONS 17 - 19
Scenario: A 58-year-old male with rheumatoid arthritis presents to the emergency department with intolerable neck pain and cervical myelopathy. On MRI, he is found to have superior migration of the odontoid (SMO) process through the foramen magnum (cranial settling) and compression of
the brainstem by the odontoid process itself.

Q : All of the following information is important to gather preoperatively in patients with craniocervical junction (GCJ) abnormalities EXCEPT?

A. The evaluation of craniocervical stability
B. EMG and nerve conduction studies (NCS) to identify
the extent of peripheral nerve damage
C. Whether there is an associated syrinx
D. The extent of ventral compression
E. Presence of abnormal ossification centers and epiphyseal growth plates in children, as this may alter
treatment strategies

Answer 17

B. EMG and nerve conduction studies (NCS) to identify

Question 18

Dynamic imaging studies of the craniocervical junction reveal instability. The neurosurgeon elects to employ gentle cervical traction for 3 days with good success in reducing the
abnormality. After 3 days of traction, the patient’s neck pain significantly improves, and MRI reveals minimal brainstem compression in the reduced position. What should be the next course of management?

A. Posterior cervical laminectomy
B. Posterior cervical laminectomy, suboccipital craniectomy, and fusion
C. Cervical traction for another week to attempt to further
reduce the abnormality before embarking on any
surgical procedure
D. Immobilization alone with posterior cervical fusion
without a decompression
E. Transoral odontectomy followed by posterior cervical decompression, suboccipital craniectomy, and fusion

Answer 18

D. Immobilization alone with posterior cervical fusion
without a decompression

Question 19

One year later the patient experiences progressive
weakness in his legs, ataxia, and bladder incontinence. His strength in the upper extremities is preserved, and he has no evidence of cranial nerve abnormalities. Plain films and CT scan of the craniocervical junction are unremarkable. What should be the next diagnostic test employed?

A. CT of the brain to look for hydrocephalus
B. EMG and NCS to identify the extent of peripheral
nerve damage
C. Screening MRI of the spine
D. Bladder urodynamic testing
E. Dynamic films of the cervical spine to evaluate for
pseudoarthrosis and instability

Answer 19

C. Screening MRI of the spine

Craniocervical
junction (CGJ) abnormalities can often be very difficult
to manage, with the primary goal being to relieve the
compression at the cervicomedullary junction. They are commonly seen in patients with Ghiari malformation or rheumatoid arthritis. With reducible lesions, stabilization is essential to maintain neural decompression, while for irreducible lesions, decompression at the site of encroachment (ventral or posterior) as well as stabilization are often
required. Patients with rheumatoid arthritis are at risk for developing atlantoaxial instability (AAI); superior migration of the odontoid process (SMO), also known as cranial settling; and subaxial subluxations (SAS). For rheumatoid patients with reducible lesions, immobilization alone with posterior spinal or craniospinal fusion without decompressive procedures is the mainstay of treatment. Late-onset deterioration in patients with rheumatoid
arthritis or Ghiari malformations in the pattern seen in this patient is concerning for syrinx or syringomyelia formation

Question 20

QUESTIONS 20 - 21

A surgeon utilizes an infratemporal fossa approach to
remove a large infiltrating tumor of the cranial base. He
comes across the shaded structure depicted by the arrow below. How many muscles attach to this structure?

A. 2
B. 3
C. 4
D. 5
E. 6

Answer 20

B. 3

Question 21

Which cranial nerves innervate these muscles?
A. VII, IX
B. VII, IX, XII
C. IX, X, XII
D. V, VII, IX
E. X,XII

Answer 21

B. VII, IX, XII

Question 22

. How many ligaments attach to this structure?
A. 1
B. 2
C. 3
D. 4
E. 5

Answer 22

B. 2

The styloid process gives rise to the stylohyoid
(VII), styloglossus (XII), and stylopharyngeal muscles
(IX) of the visceral neck as well as the stylomandibular and stylohyoid ligaments. It is a remnant of the second brachial arch

Question 23

Directions: Match each of the following questions with
the most likely fracture pattern (letterhead) depicted in, using each answer once, more than once, or not at all.

Q.A : Most likely to cause weakness of the extensor muscles of the wrist and hand; extension of forearm typically not affected; sensation of dorsal hand affected

Q.B : May result in teres minor weakness

Q.C : Weakness of flexion and adduction of wrist, paralysis of hypothenar muscles and most deep muscles of the hand, some weakness in thenar muscles

Q.D : Shoulder abduction weakness

Q.E : High likelihood of ulnar nerve injury only

Q.F : Median nerve damage, paralysis of hypothenar muscles, some thenar muscles, and most of the deep muscles of the hand; flexion and adduction of wrist spared

Q.G : Can be associated with brachial plexus injuries

Q.H : Most likely to cause combined radial, medial, and ulnar nerve injuries

Answer 23

A.-B

B.-A

C.-C

D.-A

E.-C

F.-F

G.-A

H.-D

Fracture of them proximal humerus (A) can result in injury to the axillary
nerve (G5-6), which innervates the teres minor and deltoid muscles. This can result in sensory loss at the shoulder as well as shoulder abduction weakness. There is also a chance of concomitant brachial plexus injury with such a fracture due to the proximity of the proximal humerus to the brachial plexus. The radial nerve runs down the posterior aspect of the arm and is at risk for injury during fractures of the midhumeral shaft as it winds around the spiral groove (B). This could cause paralysis of the wrist and hand extensor muscles. Since the fibers that innervate the triceps muscle often arise proximal to the spiral groove, extension of the forearm may not be affected by midhumeral fractures, and some supination is possible due to an intact biceps brachii muscle. Fracture in the vicinity of the medial epicondyle may result in ulnar nerve damage only (C), which can produce weakness of flexion and adduction of wrist, paralysis of hypothenar muscles and most deep muscles of the hand, as well as some weakness in select thenar muscles. Injury of the ulnar nerve by fracture of the distal ulna can result inweakness or paralysis of hypothenar, some thenar, and intrinsic hand muscles but often spares innervation of the wrist (flexion, adduction), since these nerves often arise more proximally. If there is also a concomitant distal radial fracture, injury to the median nerve may accompany the ulnar nerve injury (F) and produce loss of sensation of the lateral side of the palm without sensory loss on the palmar sides of the first, second, and third digits (superficial branch of the median nerve) as well as marked weakness of thumbflexion and abduction, inability to oppose the thumb, inability to fully extend the second and third digits, and sensory loss along the palmar side of the first, second, and third digits (deep branch in carpal tunnel). A fracture of the distal humerus (D) is most likely to result in combined radial,median, and ulnar nerve injuries

Question 24

A 9-year-old girl presented to her pediatrician with
headaches and a bitemporal field cut. Her MRI is depicted below. Which of the following would be true
regarding the endocrine outcome after surgical resection of this tumor?

A. There is a 30% chance that she will develop diabetes insipidus
B. The most serious and disabling problem is the development
of obesity, which occurs in about 50% of these
patients after surgery
C. Approximately 90% of patients will not require maintenance corticosteroid and thyroid replacement
therapy
D. Approximately 10% of patients will require growth
hormone replacement therapy
E. The endocrine outcome after surgery is very
unpredictable

Answer 24

B. The most serious and disabling problem is the development of obesity, which occurs in about 50% of these patients after surgery

A significant number of children with craniopharyngiomas will have a significant endocrine abnormality after
surgery, which is quite predictable. The most serious complication appears to be obesity, which develops in about 50% of patients. These patients are unable to control their appetite secondary to damage to the hypothalamic satiety center. Growth hormone may benefit these patients, as it appears to reduce body fat and increase lean body mass. Nearly 50% of patients will require GH-replacement therapy. Diabetes insipidus occurs in about 90% of patients and is often permanent. Moreover, about 90% of patients will require hydrocortisone and thyroid replacement therapy after surgery

Question 25

A 42-year-old female was recently diagnosed with
spontaneous intracranial hypotension. All of the following
are frequently associated with this problem EXCEPT?

A. The headaches often resemble a post-lumbar puncture headache
B. MRI scans with contrast may reveal enhancement of
the dura over the cerebral and cerebellar convexities
C. Spontaneous improvement is rarely seen, since CSF leaks are often identified adjacent to nerve roots
D. Spinal fluid may reveal elevated protein and pleocytosis
E. Analgesics containing caffeine may be helpful

Answer 25

C. Spontaneous improvement is rarely seen, since CSF leaks are often identified adjacent to nerve roots

The headaches of spontaneous intracranial hypotension often resemble post-lumbar puncture headaches. Headaches are usually worse in the upright position and are generally relieved when the patient is lying down. The diagnosis is established by lumbar puncture, which reveals low opening pressure or dry tap. It is not uncommon to have elevated protein and pleocytosis. It is postulated that this syndrome results from leakage of GSF to the outside neuraxis, often around nerve roots. MR cisternography is often capable of demonstrating the leak. Jugular compression will elevate intracranial pressure but usually makes the headache worse, suggesting that low pressure may not be the only factor responsible for the headaches. MRI scans often reveal dural enhancement over the cerebral and cerebellar convexities, tentorium, and falx, which usually resolves with resolution of the symptoms. Treatment should be conservative, since there is often spontaneous improvement. Analgesics containing caffeine and adequate hydration seem to help. In
some cases an epidural patch may be required; surgical closure of the fistula is rarely required

Question 26

All of the following lesions are appropriate for stereotactic
radiosurgery EXCEPT?

A. A 3-cm3 arteriovenous malformation in the brainstem
B. A 1-cm right frontal and 2-cm left parietal metastatic
carcinoma from the lung
C. Recurrent glioblastoma of the left temporal lobe (2 cm3)
D. A 1-cm cavernoma of the right caudate nucleus that
previously hemorrhaged
E. Bilateral thalamic arteriovenous malformations (3 cm3)

Answer 26

D. A 1-cm cavernoma of the right caudate nucleus that
previously hemorrhaged

A long history of radiosurgical treatment for arteriovenous malformations exists. The best responses are often obtained for lesions with volumes less than 4 cm3 . Multiple metastatic lesions are also amenable to this treatment modality, as are recurrent gliomas located in a variety of
locations including the brainstem, thalamus, or other eloquent areas. There is, however, controversy about the radiosurgical treatment of cavernomas. While disease control has been documented, some authors are concerned with the
potential of treatment-related complications such as recurrent hemorrhage after radiosurgery

Question 27

All of the following would reduce pain conduction or a
patient’s reaction to pain EXCEPT?

A. Stimulation of the periaqueductal gray
B. Prefrontal lobotomy
C. Cingulotomy
D. Hippocampectomy
E. Ventrolateral cordotomy

Answer 27

D. Hippocampectomy

Prefrontal lobectomy, cingulotomy, ventrolateral
cordotomy, and periaqueductal gray stimulation may interrupt
pain pathways or the response to painful stimuli.
Hippocampectomy does not interrupt these pathways but
may decrease the severity of complex partial seizures

Question 28

A 34-year-old female is involved in a motor vehicle collision, suffers a severe closed head injury and
develops a significant posttraumatic tremor in the right arm. Although posttraumatic tremors are generally difficult to manage, which surgical procedure may help control tremors, which are otherwise refractory to medical therapy?

A. Thalamic stimulation
B. Subthalamic nucleus stimulation
C. Motor cortex stimulation
D. Capsulotomy
E. Multiple subpial transections

Answer 28

A. Thalamic stimulation

Traumatic injury to the brainstem including the superior cerebellar peduncles and their connections can result
in severe tremor that may be delayed by weeks to months following the brain injury. In some cases, improvement or resolution occurs spontaneously, so some authors have recommended a period of observation before considering surgery. The largest published series for secondary tremors is among patients with multiple sclerosis, although a growing body of information is now available for patients with posttraumatic tremors. With posttraumatic tremors, thalamic
stimulation (Vim) may be considered for those who are refractory to medical management, although results have been mixed. Thalamotomy is another treatment option for this group of patients, although postoperative dysarthria or worsening pre-existing dysarthria is an especially troubling complication in some of these studies

Question 29

A 36-year-old female has a complex aneurysm that
requires the use of cardiac arrest and profound hypothermia during surgery. All of the following are potential physiologic effects of profound hypothermia EXCEPT?

A. Increased blood viscosity
B. Hyperglycemia
C. Decreased corticosteroid release
D. Complement-mediated pneumonitis
E. Hypercoagulable state

Answer 29

E. Hypercoagulable state

Profound hypothermia during circulatory arrest can
result in various physiologic effects including increasing blood viscosity, metabolic acidosis (underperfused tissue), hyperglycemia (secondary to hypoinsulinemia), decreased corticosteroid secretion, complement-mediated pneumonitis, renal failure (due to transient decrease in glomerular filtration rate, hemolysis, and blood product reactions), hepatic failure, and hypothermia-induced coagulopathy (due to platelet dysfunction and slowing of the enzymatic clotting cascade)

Question 30

What is the most common physical manifestation of the
abnormality depicted by the angiogram below ?

A. Neck pain
B. Cervical bruit
C. Contralateral arm weakness or numbness
D. Dysesthesia
E. Transient vision loss

Answer 30

B. Cervical bruit

The most common physical manifestation of extracranial carotid artery disease is a cervical bruit. The degree of stenosis necessary to produce a bruit has been reported to be as low as 25%, but in various studies its presence has been found to indicate a significant level (> 50%) of stenosis on angiography in at least 70% of patients. False-positive rates of 10 to 40% and false-negative rates of 30 to 70% have been reported for cervical bruits. The Framingham Study found that the risk of stroke and TIAs in patients with bruits was two to three times the risk for patients without bruits. Such patients were also about 2.5 times more likely to have a heart attack and 1.9 times more likely to die during the study period

Question 31

QUESTIONS 31-33

Refer to Figure , What is the most likely
diagnosis?

A. Echinococcus infection
B. Neurocysticercosis
C. Cryptococcus infection
D. Cytomegalovirus infection
E. Trichinosis

Answer 31

B. Neurocysticercosis

Question 32

This patient is most likely to present with?
A. Headaches
B. Obtundation
C. Cranial nerve palsies
D. Fevers
E. Seizure

Answer 32

E. Seizure

Question 33

This disorder is caused by

A. Borrelia burgdorferi
B. Echinococcus granulosa
C. Toxoplasma gondii
D. Treponema pallidum
E. Taenia solium

Answer 33

E. Taenia solium

Neurocysticercosis (NGG) is the most common
parasitic infection of the central nervous system (CNS) worldwide. Humans are the definitive host for the adult tapeworm Taenia solium, which thrives in the small intestine
without consequence. Fecal shedding of eggs usually leads to ingestion of eggs in contaminated water or food by an intermediate host, typically humans or pig. Once inside the intestine, the eggs are released and produce primary larvae that enter the circulatory system. Hematogenous spread to muscular, ocular, and neural tissue then occurs. Once inside the
brain, the primary larvae develop into secondary larvae, the cysticerci. Clinical manifestations of the neural form of
the disease are varied and nonspecific. This pleomorphism is related to the number, size, and topography of the lesions. Parenchymal disease (as in this case) is most common and presents with seizures in 50 to 80% of patients. Treatment typically includes antiepileptics, albendazole, or praziquantel, as well as a short course of steroids to reduce the
inflammatory reaction during antihelminthic treatment.
Niclosamide may be given orally to treat adult tapeworms in the Gl tract. Fluconazole is an antifungal and not used to treat this disease process. The colonization of the ventricular system often presents with rapid clinical deterioration due to increased intracranial pressure from obstructive hydrocephalus. There is still controversy about the best treatment
for this form of the disease, but most authors advocate either a trial of antihelminthic medication, endoscopic cyst resection, or microsurgery. Subarachnoid disease is usually more difficult to manage because the cysts are usually multiple, attain larger sizes, and produce severe basal meningitis, but antihelminthic medications are typically first-line therapy for this form of the disease. From the many tests performed, current data indicate that enzyme-linked immunosorbent assay (ELISA) and electroimmunotransfer blot (EITB) tests are the most effective laboratory tests for diagnosis. Peripheral white blood cells, ova and parasites in stool, and eosinophilia are inconsistent and unreliable markers of disease. This patient also harbored a fourth ventricular cyst and
obstructive hydrocephalus, which accounts for the rounded third ventricle

Question 34

What is the most likely diagnosis depicted by the
angiogram below (Figure 6.80Q)?

A. Blue rubber bleb nevus syndrome
B. Vein of Galen aneurysm
C. Carotid-cavernous fistula
D. Intracranial hemangioblastoma of infancy
E. Sinus pericranii

Answer 34

B. Vein of Galen aneurysm

A neonate suffering high-output cardiac failure,
hyperdynamic precordium, dilated cervical and cranial
veins, and arteries with a “machine-like” bruit heard over the head and neck is most likely harboring a vein of Galen aneurysm. Vascular tumors, CC fistula, blue rubber bleb nevus syndrome, and sinus pericranii do not typically present with this constellation of problems. Although transcranial ultrasonography is an excellent way to diagnose these lesions, the “gold standard” is cerebral angiography. In infants, a transarterial and transvenous route to eliminate the high-flow shunt is often employed. This technique may not lead to complete obliteration but often converts highoutput cardiac failure to a persistent fistula. In an older child
or adult, the treatment is frequently gradual and entails graded elimination of the shunt with endovascular surgery, usually via a transarterial route

Question 35

The posterior interosseous nerve supplies all of the
following muscles EXCEPT?
A. Supinator
B. Extensor carpi ulnaris
C. Abductor pollicis longus
D. Extensor digitorum
E. Pronator quadratus

Answer 35

E. Pronator quadratus

The deep branch of the radial nerve passes through a
slit in the supinator muscle (arcade of Frohse) to the posterior forearm. After passing this slit, the nerve is called the posterior interosseous nerve and supplies the supinator, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris, abductor pollicis longus, extensors pollicis longus and brevis, and extensor indicis muscles. The anterior interosseous nerve, a branch of the median nerve, supplies the pronator quadratus

Question 36

The ability to create irregularly shaped radiosurgical
volumes is important to achieve conformal irradiation of target tissue. Which of the following techniques can be employed to create such plans?

A. Combine multiple isocenters of irradiation in different planes
B. Individual isocenters can be weighted variably to
change their relative shape
C. Individual radiation beams can be blocked to restrict
dose away from critical structures, such as the optic
chiasm
D. A and B only
E. All of the above

Answer 36

E. All of the above

The ability to create irregularly shaped radiosurgical
volumes is important to achieve conformal irradiation of
target tissue, as all tumors or lesions are rarely perfect
spheres. The following techniques can be used to create an irregularly shaped plan during radiosurgery. First, combine multiple isocenters of irradiation in different planes. For example, a series of 4-mm isocentors of irradiation is
often used to tailor radiation to the porus acusticus for
schwannomas. Second, individual isocenters can be weighted variably to change their relative shape. Finally, individual radiation beams can be blocked to restrict dose away from critical structures, such as the optic chiasm

Question 37

QUESTIONS 37-38
A 45-year-old female undergoes a C5-6 and C6-7 anterior cervical discectomy and fusion. Postoperatively, she awakens with a Horner’s syndrome. The most likely etiology of this finding was related to damage of what structure(s)?

A. Sympathetic nerves running along the carotid artery
during neck dissection
B. Injury of the Tl nerve root during the discectomy
C. Interruption of the sympathetic chain located on the
anterior surface of the longus colli muscles
D. Spinal cord injury during surgery
E. A small hypothalamic infarct during surgery

Answer 37

C. Interruption of the sympathetic chain located on the
anterior surface of the longus colli muscles

A rare complication after anterior cervical procedures
is the development of a Horner’s syndrome (anhidrosis,
miosis, ptosis) from interruption of the sympathetic chain
located on the anterior surface of the longus colli muscle.
The thoracic duct enters the subclavian vein on the left and is particularly vulnerable to injury during left-sided anterior cervical procedures

Question 38

A left-sided approach decreases the risk of recurrent
laryngeal nerve palsy during anterior cervical procedures,
but at lower levels in the neck a left-sided approach runs the risk of injuring what structure?

A. Inferior laryngeal nerve
B. Thyrocervical artery
C. Thoracic duct
D. C5 nerve root
E. Dominant cardiac accelerator nerves

Answer 38

C. Thoracic duct

A rare complication after anterior cervical procedures
is the development of a Horner’s syndrome (anhidrosis,
miosis, ptosis) from interruption of the sympathetic chain
located on the anterior surface of the longus colli muscle.
The thoracic duct enters the subclavian vein on the left and is particularly vulnerable to injury during left-sided anterior cervical procedures

Question 39

Degenerative spondylolisthesis is most common at what
level in the lumbar spine?
A. Ll-2
B. L2-3
C. L3-4
D. L4-5
E. L5-S1

Answer 39

D. L4-5

Degenerative spondylolisthesis is most common in
women at the L4-5 level, but may also be seen at the L3-4 level. Because this often occurs with sacralization of L5 in many patients, the facet degeneration may be explained as a hypermobility syndrome

Question 40

A 72-year-old female with rheumatoid arthritis is found
to have a reducible atlantoaxial dislocation after 36 hours of cervical traction. There is minimal ventral compression from pannus formation, no cranial settling, and no foramen magnum stenosis noted on MR scan. What is the best treatment strategy for this patient?

A. Transarticular screw fixation and fusion if the lateral
atlantal masses are intact with good-quality bone
B. Transoral odontectomy followed by posterior occipitalcervical
decompression and fusion
C. Laminectomy
D. Transoral odontecto

Answer 40

A. Transarticular screw fixation and fusion if the lateral
atlantal masses are intact with good-quality bone

Irreducible pathologic conditions affecting the cervicomedullary
junction in patients with rheumatoid arthritis
frequently require an anterior cervical procedure to remove the offending pathology (frequently pannus formation), followed by dorsal fixation and fusion. Reducible atlantoaxial
dislocation is best managed by a posterior fusion and fixation procedure. Usually transarticular screw fixation is desirable if the bone quality is good and the lateral masses of the atlas are intact: but if this is not the case, placement of a rectangle of bone between the posterior arch of C2 and CI followed by wiring may be an option. This, however, has been associated with higher failure rates in some studies. These patients often required further reinforcement with cervical immobilization techniques such as halo placement. Dorsal occipitocervical fusion is almost always required for patients with rheumatoid cranial settling and in those following rheumatoid pannus resection. Transoral odontectomy with or without posterior fusion is not required for
this patient since there was a reducible lesion. Laminectomy alone would likely further destabilize this patient, while
halo placement without fusion would run a very high risk of failure

Question 41

The ideal bone graft provides all of the following elements
for successful healing EXCEPT?

A. Osteoconductive matrix
B. Osteoinductive factors
C. To support viable osteogenic cells
D. Structural support
E. Osteoblasts for bone healing

Answer 41

E. Osteoblasts for bone healing

The ideal bone graft provides the following elements
for successful healing: osteoconductive matrix, osteoinductive factors, viable osteogenic cells, and structural support. Only fresh autografts contribute viable osteogenic cells to
the developing fusion. Processed allografts frequently have no living cellular elements and are mainly derived from the tissues of the recipient bed

Question 42

Interfering with uptake of which ion into cells during
severe closed head injury has resulted in a significant clinical benefit?
A. Ga2+
B. Na+
c. cr
D. K+
E. None of the above

Answer 42

E. None of the above

Although traumatic brain injury (TBI) has been
shown to result in increases of calcium flux into cells with
subsequent cell injury, no clinical benefit has been observed in clinical trials attempting to attenuate this response in patients with TBI. A subset of patients with subarachnoid
hemorrhage, however, did show a benefit. Calcium may
enter cells via ion channels influenced by excitatory amino acids (glutamate, aspartate). Unfortunately clinical trials to antagonize these receptors have been discouraging in TBI

Question 43

Surgical therapies used for dystonia have traditionally
included all of the following EXCEPT?
A. Peripheral denervation
B. Pallidotomy
C. Thalamotomy
D. Dorsal column stimulation
E. Motor cortex stimulation

Answer 43

E. Motor cortex stimulation

Surgical therapies including cerebellar stimulation,
dorsal column stimulation, peripheral denervation, thalamotomy, and pallidotomy have been used in the past to
treat various forms of dystonia. Although the thalamus has been the primary target for years, more recently many surgeons are targeting the globus pallidus with good results.
Medications such as anticholinergics, muscle relaxants, and benzodiazepines are of limited use to patients. Botulism
toxin is a safe and effective therapy for many focal dystonias but has not proven effective for patients with segmental dystonia, hemidystonia, or generalized dystonia

Question 44

All of the following surgical procedures have been
employed to treat neuropsychiatric illness and behavioral
disorders EXCEPT?
A. Arcuate fasciculotomy
B. Subcaudate tractotomy
C. Limbic leukotomy
D. Anterior capsulotomy
E. Anterior cingulotomy

Answer 44

A. Arcuate fasciculotomy

The surgical management of psychiatric disease
can be helpful for select patients with treatment-refractory
major affective disorders, obsessive-compulsive disorder, and chronic anxiety states. Surgical interventions have
included anterior capsulotomy, limbic leukotomy, subcaudate tractotomy, and anterior cingulotomy but not arcuate
fasciculotomy

Question 45

The superior semicircular canal projects into the floor of
the middle cranial fossa as what structure often seen during a subtemporal approach for acoustic neuroma resection?
A. Arcuate eminence
B. Tegmen tympani
C. Vestibule
D. Vertical crest
E. Vestibular prominence

Answer 45

A.Arcuate eminence

The superior semicircular canal projects into the floor
of the middle cranial fossa as the arcuate eminence

Question 46

QUESTIONS 46 - 48
Scenario: A 45-year old male undergoes a subtemporal
approach for tumor resection with elevation of the dura from the middle fossa floor and petrous bone.

Q : Structures visible on the floor of the middle cranial
fossa during this exposure may include all of the following EXCEPT?
A. Middle meningeal artery
B. Trigeminal nerve (V3)
C. Lesser superficial petrosal nerve
D. Hypoglossal nerve
E. Greater superficial petrosal nerve

Answer 46

D. Hypoglossal nerve

Question 47

Postoperatively, the patient has decreased lacrimation
on the ipsilateral side. What is the most likely etiology of this problem?
A. Lesser petrosal nerve injury
B. Greater petrosal nerve injury
C. Geniculate ganglion injury
D. Chorda tympani injury
E. Injury of Jacobson’s nerve

Answer 47

B. Greater petrosal nerve injury

Question 48

During surgery, additional exposure is needed to access
the upper petroclival region for tumor resection. Which
maneuver may assist the surgeon in accomplishing this
task?

A. Further drilling of Glasscock’s triangle
B. Additional exposure through Kawase’s quadrilateral
C. Further drilling of the arcuate eminence
D. Identifying Trautmann’s triangle and exposing
medially to this landmark
E. Modifying the approach by utilizing a presigmoid
corridor

Answer 48

B. Additional exposure through Kawase’s quadrilateral

Structures often visible on the middle
fossa floor during subtemporal approach include the middle meningeal artery (often sacrificed by cautery and packing of the foramen spinosum), trigeminal nerve (V3), lesser superficial petrosal nerve, greater superficial petrosal nerve, ICA (if there is a small dehiscence in the bone), as well as the arcuate eminence, which overlies the superior semicircular canal. Decreased tearing after surgery most likely resulted from injury of the greater superficial petrosal nerve, which provides parasympathetic supply to the lacrimal and nasal gland. Additional exposure to the posterior fossa during a subtemporal
approach may be gained by removing the bone of Kawase’s quadrilateral located in the medial petrous apex, medial to Glasscock’s triangle. Kawase’s quadrilateral is bounded laterally by the greater superficial petrosal nerve, medially by the petrous ridge and V3 of the trigeminal nerve, and at its base by the arcuate eminence. Glasscock’s triangle is bounded laterally by a line from the foramen spinosum to the facial hiatus, medially by the GSPN, and at its base by the mandibular division of the trigeminal nerve

Question 49

What is the most likely mechanism accounting for the
Cushing response?
A. Herniation of the cerebellar tonsils through the foramen magnum
B. Brainstem distortion
C. Large hemispheric insult
D. Hypoxia of the brainstem
E. Posterior fossa mass

Answer 49

D. Hypoxia of the brainstem

The Gushing response consists of the triad of hypertension, bradycardia, and an irregular breathing pattern. According to many authors, the most likely mechanism accounting for this response is reduction in oxygenation in an area just rostral to the medulla. For this reason it is also called the ischemic response

Question 50

What is the most common clinical manifestation of the
abnormality depicted on the angiogram below ?

A. Hoarseness
B. Dysphagia
C. Unilateral tongue atrophy
D. Palpable neck mass
E. Hypertension

Answer 50

D. Palpable neck mass

The most common clinical presentation of carotid
body tumors is a palpable neck mass in the high cervical region. Less commonly patients present with hoarseness, dysphagia, and unilateral tongue atrophy and weakness due to the tumors’ proximity to the vagus and hypoglossal nerves. These tumors are generally benign, although they do tend to locally invade adjacent tissue, which can make their resection difficult. An evaluation of the endocrine system may
be warranted, especially in patients with hypertension and tachycardia. Some patients may harbor a pheochromocytomalike
lesion that secretes excess catecholamines. In such
patients, a-adrenergic blockade must be started about 2 weeks preoperatively to control hypertension, tachycardia, and the potential for arrhythmia. Preoperative planning is critical in these patients to reduce comorbidity. Some may require preoperative embolization to reduce the amount of bleeding during surgery

Question 51

Clinicians must be aware of what endocrine comorbidity
in evaluating patients with this tumor?
A. Diabetes insipidus
B. Pheochromocytoma
C. Hyperprolactinemia
D. Phenylketonuria
E. None of the above

Answer 51

The most common clinical presentation of carotid
body tumors is a palpable neck mass in the high cervical region. Less commonly patients present with hoarseness, dysphagia, and unilateral tongue atrophy and weakness due to the tumors’ proximity to the vagus and hypoglossal nerves. These tumors are generally benign, although they do tend to locally invade adjacent tissue, which can make their resection difficult. An evaluation of the endocrine system may
be warranted, especially in patients with hypertension and tachycardia. Some patients may harbor a pheochromocytomalike
lesion that secretes excess catecholamines. In such
patients, a-adrenergic blockade must be started about 2 weeks preoperatively to control hypertension, tachycardia, and the potential for arrhythmia. Preoperative planning is critical in these patients to reduce comorbidity. Some may require preoperative embolization to reduce the amount of bleeding during surgery

Question 52

What is the most common neurologically related complication after vagal nerve stimulator placement?

A. Facial numbness
B. Bradycardia
C. Dysphonia
D. Hypotension
E. Short-lived arrhythmia

Answer 52

C. Dysphonia

The most common surgical complication after vagal
nerve stimulator (VNS) placement is infection. Transient vocal cord paralysis with hoarseness and swallowing problems is the second most common surgical complication of VNS. Temporary lower face numbness and weakness occur in about 0.7% of patients, likely related to high cervical incisions
and superficial nerve injury

Question 53

Which of the following statements concerning stabilization of the lumbar spine with segmental pedicle screw fixation is correct?

A. The lateral stability is significantly enhanced if the
pedicle screw angle is 30 degrees or greater
B. The use of transfixation increases the rotational but
not the lateral load stability of the construct
C. Without a transfixator, the vertebral column is stable
in lateral load
D. None of the above
E. All of the above

Answer 53

A. The lateral stability is significantly enhanced if the
pedicle screw angle is 30 degrees or greater

The internal stabilization of two adjacent segments
of the lumbar spine with a pedicle screw construct having a pedicle-to-pedicle screw angle of zero and no transfixitor is not stable in lateral or rotational load, as each of the screws are free to turn in their screw holes in the body. Stability can be enhanced by the application of a transfixitor or angling
the screws inward to form a pedicle-to-pedicle screw angle of 30 degrees

Question 54

A 45-year-old male has a long history of epilepsy from
seizure foci originating in the right premotor cortex and
extending into the adjacent motor cortex. His seizures have remained refractory to a variety of antiepileptic drugs, and he was referred to a neurosurgeon to discuss surgical options. EEG recordings reveal a seizure focus in the left premotor region that extends to the adjacent motor cortex. Which of the following surgical procedures may be performed concomitantly during lesionectomy to avoid major injury to the motor cortex and help control his seizures?

A. Topectomy
B. Limited lesionectomy
C. Motor cortex stimulation
D. Multiple subpial transections

Answer 54

D.

Multiple subpial transection (MST) was developed as a procedure to address seizure activity that extends beyond the area of resection and into eloquent cortex. The cerebral cortex has functional vertical columns, with its vertical orientation of incoming and outgoing fibers. Seizures, however,
are believed to spread horizontally through the cortex. MST involves disconnecting the vertical columns of the cerebral cortex, which inhibits synchronization and spread of the 208 Intensive Neurosurgery Board Review
seizure focus with minimal injury to the cortex. The most common problem faced by patients after this procedure includes subtle, transient deficits corresponding to the area of resection that typically improve. Permanent complication rates after this procedure are in the order of 5%