Pediatric Neurosurgery

Question 1

What structure is indicated by the arrow in this image from an endoscopic third ventriculostomy?
A. Optic chiasm
B. Pituitary stalk
C. Tip of basilar artery
D. Fornix
E. Mammillary bodies

Answer 1

E. Mammillary bodies

Question 2

During an infratentorial supracerebellar approach to a pineal tumor, what vein in the galenic draining group may be sacrificed safely without negative sequelae?
A. Basal vein of Rosenthal
B. Posterior mesencephalic vein
C. Straight sinus
D. Precentral cerebellar vein
E. Internal cerebral vein

Answer 2

D. Precentral cerebellar vein

The vein of the cerebellomesencephalic fissure
(also called the precentral cerebellar vein) is
formed by the union of the paired veins of the
superior cerebellar peduncles, and ascends through
the quadrigeminal cistern to drain into the vein
of Galen, either directly or through the superior
vermian vein.

Question 3

A premature neonate’s head ultrasound demon- strates intraventricular hemorrhage. The ventricles are dilated mildly. What is the infant’s subependy- mal hemorrhage grade?
A. Grade 1
B. Grade 2
C. Grade 3
D. Grade 4

Answer 3

C. Grade 3

A grade 3 hemorrhage also extends into the ventricles, and there is ventricular dilation. (A) A grade
1 hemorrhage does not extend beyond the subependyma. (B) A grade 2 hemorrhage extends into
the ventricles, but they are not dilated. (D) A grade
4 hemorrhage includes intraventricular hemorrhage with intraparenchymal extension.

Question 4

A 3-year-old boy presents with a history of spinal cord de-tethering and excision of a thoracic der- mal sinus tract during infancy. What is the most likely spinal cord lesion seen on the current T2 MRI shown in this image?
A. Syrinx
B. Ependymoma
C. Astrocytoma
D. Dermoid tumor
E. Epidermoid tumor

Answer 4

D. Dermoid tumor

Congenital dermal sinus tracts are a type of
closed spinal dysraphism in which an epithelium-lined sinus tract from the dorsal skin surface
extends inward for a variable distance. Thoracic and
cervical regions, where the neural folds fuse first,
are the rarest sites for dorsal dermal sinus tracts, whereas lumbosacral and occipital dermal sinus
tracts are relatively frequent. Spinal canal dermoid
tumors can be seen in association with dorsal dermal sinus tracts. Surgical excision can lead to cure
of these lesions and can de-tether the spinal cord.

Question 5

What component is necessary to classify a Chiari malformation as type 3?
A. Cervical cord syrinx
B. Occipital encephalocele
C. Lumbar myelomeningocele
D. Cerebellar vermian agenesis
E. Platybasia

Answer 5

B. Occipital encephalocele

A Chiari type 3 malformation includes a suboccipital encephalocele with herniation of all brainstem structures into the foramen magnum as well
as through a defect in the posterior fossa wall (posterior fossa encephalocele). A Chiari type 4 malformation typically refers to an extreme hypoplasia
or frank aplasia of the cerebellum. (A) Cervical cord syringes can occur with any type of Chiari malformation. (C) Chiari type 2 malformations occur in more than 95% of patients with myelomeningoceles, which are exclusive to this population of Chiari malformation patients. (D) Cerebellar vermian agenesis occurs in Dandy-Walker malformation. (E) Platybasia is “flat clivus” and is seen in Paget disease.

Question 6

A 2-year-old boy presents with gait imbalance and progressive headaches. MRI suggests a posterior fossa tumor. Gross total resection and pathological analysis reveal an average risk medulloblastoma. The next adjuvant therapy step is:
A. Chemotherapy alone
B. Radiation therapy alone
C. Concomitant chemotherapy and radiation
D. No need for further adjuvant therapy

Answer 6

A. Chemotherapy alone

Children with medulloblastoma who are at least
3 years of age should receive radiation to the tumor
site and the complete craniospinal axis, as well as
chemotherapy. Children younger than 3 years of
age typically are managed with chemotherapy until
they reach the age of 3, at which time radiation is
considered. This delay is due to the severe detrimental effects of radiation on the immature, developing nervous system

Question 7

An 8-year-old child with a history of myelomenin- gocele repair after birth presents with progressive leg weakness and a neurogenic bladder. An MRI of lumbar spine, shown in this image, suggests:
A. Syringomyelia secondary to a tethered spinal cord
B. Idiopathic syringomyelia
C. Spinal lipoma
D. Dermoid tumor
E. Thickened filum terminale

Answer 7

A. Syringomyelia secondary to a tethered spinal cord

Tethered spinal cord syndrome is a neurologic
disorder caused by tissue attachments that limit
the movement of the spinal cord within the spinal
column during growth. These attachments cause
an abnormal stretching of the spinal cord. This
syndrome is associated closely with spina bifida. It
is estimated that 30% of children with spina bifida
defects repaired shortly after birth will require
surgery at some point to untether the spinal cord
later during childhood.

Question 8

A 2-month-old baby has a slowly growing midline mass over the anterior fontanelle, as shown in the MRI in this image. The most likely diagnosis is:
A. Dermoid cyst
B. Eosinophilic granuloma
C. Epidermoid cyst
D. Fibrous dysplasia
E. Hemangioma

Answer 8

A. Dermoid cyst

Dermoid and epidermoid cysts are the most common lesions of the scalp and calvarium encountered in the pediatric population. They account for
15 to 60% of masses in this region. Dermoid cysts
and dermal tracts are more likely to involve the
scalp and skull in young children, whereas epidermoid cysts tend to occur intracranially in older
children and young adults. In addition, dermoid
cysts typically are in the midline, whereas epidermoid cysts tend to occur off the midline.

Question 9

A 3-month-old baby has an abnormal head shape. Based on the 3D reconstruction imaging of the skull, shown in this image, what syndrome is suspected?
A. Pierre Robin syndrome
B. Treacher Collins syndrome
C. Pfeiffer syndrome
D. Goldenhar syndrome
E. Moebius syndrome

Answer 9

C. Pfeiffer syndrome

Fusion of both coronal sutures leads to a head
shape called brachycephaly. This causes restriction
of the growth of the anterior fossa, resulting in a
shorter and wider than normal skull. Compensatory vertical growth also occurs, which is called
turricephaly. Bicoronal synostosis often is seen
in patients with associated syndromes, such as
Crouzon, Apert, Saethre-Chotzen, Muenke, and
Pfeiffer syndromes. (A) Pierre Robin syndrome is
a sequence of developmental events that result
from a small mandible and tongue abnormalities
and involve airway obstruction. (B) Treacher Collins syndrome is an autosomal dominant condition
resulting in craniofacial abnormalities. (D) Goldenhar syndrome involves the incomplete development
of the nose, lips, soft palate, jaw, and ears. (E) Moebius syndrome is characterized by congenital facial
weakness.

Question 10

The normal level of conus medullaris in infants and children is at the level of
A. L1-L2
B. L3-L4
C. L4-L5
D. L5-S1
E. T12-L1

Answer 10

A. L1-L2

Embryologically, ascent of the conus medullaris
results in the tip of the conus lying most commonly
opposite the L1-L2 disk space. A conus medullaris
below the mid-body of L2 is considered to be tethered radiographically.

Question 11

The most common postoperative complication encountered after selective dorsal rhizotomy for spasticity is:
A. Cerebrospinal fluid leak
B. Paraplegia
C. Bladder incontinence
D. Bowel incontinence
E. Lower extremity hyperesthesia

Answer 11

E. Lower extremity hyperesthesia

The major (although uncommon) complications
of selective dorsal rhizotomy include paraplegia,
sensory loss, cerebrospinal leak, bladder and bowel
incontinence, and infection. Many patients may
experience hyperesthesia in the legs for several
months.

Question 12

The most life-threatening complication during endoscopic third ventriculostomy for obstructive hydrocephalus is secondary to:
A. Forniceal injury
B. Thalamic injury
C. Injury to the basilar artery bifurcation
D. Meningitis
E. Oculomotor nerve injury

Answer 12

C. Injury to the basilar artery bifurcation

Overall, the complication rate after an endoscopic
third ventriculostomy is about 2 to 15%, with most of the complications resulting only in temporary
morbidities. Complications include fever, bleeding, hemiparesis, gaze palsies, memory disorders,
altered consciousness, diabetes insipidus, weight
gain, and precocious puberty. Intraoperative neural
injuries such as thalamic, forniceal, hypothalamic,
and midbrain injuries also are observed. Intraoperative fatal hemorrhage due to basilar artery injury
and rupture has been reported. Forniceal and other
neural injuries can be avoided with proper bur
hole planning and placement

Question 13

The most common location of atypical teratoid/ rhabdoid tumors during infancy and childhood is in the:
A. Suprasellar region
B. Spinal cord
C. Posterior fossa
D. Frontal lobe
E. Temporal lobe

Answer 13

C. Posterior fossa

Central nervous system atypical teratoid/rhabdoid
tumors (ATRTs) are rare, clinically aggressive tumors
that most often affect children aged 3 years or
younger but can also occur in older children and
adults. About one half of ATRTs arise in the posterior fossa.

Question 14

What surgical procedure should be considered as a treatment option in pediatric patients with dis- abling drop attacks and generalized seizures?
A. Anatomic hemispherectomy
B. Functional hemispherectomy
C. Mesial temporal lobectomy
D. Amygdalohippocampectomy
E. Corpus callosotomy

Answer 14

E. Corpus callosotomy

Corpus callosotomy (typically involving the resection of the anterior two thirds of the corpus callosum) should be considered as a treatment option
in pediatric patients with disabling drop attacks and
generalized seizures. Although vagal nerve stimulation (VNS) has comparable results in controlling
drop attacks, corpus callosotomy is a viable option in patients who do not respond well to VNS.

Question 15

The most common symptomatic intracranial vas- cular anomaly in children is a(n):
A. Arteriovenous malformation (AVM)
B. Cavernoma
C. Venous angioma
D. Berry aneurysm
E. Mycotic aneurysm

Answer 15

A. Arteriovenous malformation (AVM)

Arteriovenous malformations are the most common symptomatic intracranial vascular abnormality
in children. They consist of direct artery-to-venous
connections without intervening capillaries, and
they occur in the cerebral hemispheres, brainstem,
and spinal cord. Hemorrhagic events from AVMs in
childhood have been associated with a 25% mortality rate

Question 16

What particular spinal feature is associated with achondroplasia?
A. Scalloping of the vertebrae
B. Hemivertebrae
C. Foramen magnum stenosis
D. Os odontoideum
E. Dermal sinus tract

Answer 16

C. Foramen magnum stenosis

Foramen magnum stenosis is a common finding
in children with achondroplasia, resulting in severe
compromise of cerebrospinal fluid flow at the cervicomedullary junction and brainstem compression
in severe cases. Surgical decompression is recommended for patients with brainstem dysfunction.

Question 17

An 11-month-old boy presents with macrocrania and failure to thrive. An MRI of the brain, shown in this image, confirms what likely type of hydrocephalus?
A. Communicating hydrocephalus
B. Obstructive hydrocephalus secondary to a
Dandy-Walker malformation
C. Obstructive hydrocephalus secondary to aque-
ductal stenosis
D. Obstructive hydrocephalus secondary to a pos-
terior fossa tumor
E. Obstructive hydrocephalus secondary to a vein
of Galen aneurysm

Answer 17

C. Obstructive hydrocephalus secondary to aque-
ductal stenosis

Idiopathic aqueductal stenosis is the most
common cause of noninfectious obstructive hydrocephalus during infancy. Endoscopic third ventriculostomy commonly is recommended as surgical
treatment, although success rates decrease when the procedure is performed in children younger than 1 year of age.

Question 18

A 10-year-old boy presents with progressive weak- ness of his bilateral wrist and finger extensors (wrist drop). He also has abdominal pain. What is the most likely source of his chemical poisoning?
A. Lead
B. Arsenic
C. Mercury
D. Copper
E. Iron

Answer 18

A. Lead

Lead intoxication often results in progressive
weakness of the bilateral wrist and finger extensors (wrist drop). Other symptoms include seizures,
psychiatric changes, abdominal pain, and anemia
(with basophilic stippling of red blood cells).
Patients with lead poisoning exhibit increased
urinary excretion of lead and porphobilinogen.
Treatment with chelators, including EDTA, penicillamine, and BAL, results in a gradual improvement of the neuropathy.

Question 19

What molecular subgroup of medulloblastoma is associated with the best 5-year overall survival rate?
A. Wnt subgroup
B. SHH subgroup
C. Group 3
D. Group 4

Answer 19

A. Wnt subgroup

Prognosis differs markedly across medulloblastoma tumor subgroups. The Wnt subtype has a
high 5-year overall survival rate that can exceed
90%, with the current standard therapy consisting
of maximal safe surgical resection of the tumor,
risk-adapted radiation therapy, and adjuvant chemotherapy. (C) By contrast, group 3 tumors have a
substantially worse prognosis, with a 5-year overall survival rate ranging from 40 to 60%. (B, D) The
other two subgroups of medulloblastoma (the
SHH subtype and group 4 tumors) have an intermediate overall survival rate at 5 years after treatment of around 75%, which varies depending on
the presence or absence of metastatic disease and
molecular abnormalities, and on the histological
category.

Question 20

Trilateral retinoblastoma describes bilateral ocular retinoblastomas and a(n):
A. Astrocytoma
B. Medulloblastoma
C. Neurofibroma
D. Optic nerve sheath tumor
E. Pineoblastoma

Answer 20

E. Pineoblastoma

Trilateral retinoblastoma is a malignant midline
primitive neuroectodermal tumor (PNET) occurring
in patients with inherited uni- or bilateral retinoblastoma. In most cases, trilateral retinoblastoma
presents as pineoblastoma.

Question 21

A pregnant woman presents after a pelvic MRI, shown in this image, evaluated a fetal spina bifida lesion detected by ultrasound. She is being consid- ered for a fetal in-utero repair. What are the ges- tational age limits (minimum and maximum) for consideration of fetal repair per the MOMs trial criteria?
A. 15 through 20 weeks
B. 19 through 26 weeks
C. 20 through 25 weeks
D. 25 through 28 weeks
E. 30 through 35 weeks

Answer 21

B. 19 through 26 weeks

Results of the MOMs trial (published in 2011)
suggest a 50% reduction in shunted hydrocephalus
at 12 months of age and improved Chiari 2 malformations when fetuses underwent in-utero repair of myelomeningoceles between 19 and 26 weeks of gestational age.

Question 22

A 10-year-old boy presents with chronic neck pain. The CT shown in this image suggests atlantoaxial instability due to:
A. Acute odontoid fracture
B. Os odontoideum
C. Clival chordoma
D. Condylar fracture
E. Ligamentous injury

Answer 22

B. Os odontoideum

Os odontoideum is an uncommon craniovertebral junction abnormality characterized by a separate ossicle superior to the dens. On CT, a smooth,
well-corticated ossicle is seen at the superior ossicle
of a hypoplastic dens. The condition is hypothesized to be a result of previous trauma in some
cases.

Question 23

What is the most common pathogen implicated in neonatal meningitis?
A. Haemophilus influenzae
B. Listeria species
C. Neisseria meningitidis
D. Staphylococci
E. Streptococci

Answer 23

E. Streptococci

Gram-negative bacilli and group B Streptococci
are the most common pathogens implicated in
neonatal meningitis.

Question 24

What is the most common asymptomatic side effect of ventriculopleural shunts?
A. Pleural effusion
B. Shunt disconnection
C. Subdural hematoma
D. Shunt infection
E. Tension pneumothorax

Answer 24

A. Pleural effusion

Ventriculopleural shunts are considered safe
alternatives to ventriculoperitoneal or ventriculoatrial shunts. Asymptomatic, mild pleural effusions frequently are encountered with shunting to
the pleural space; however, symptomatic pleural
effusions are abnormal. In most cases, the effusion
resolves spontaneously, seldom requiring specific
treatment. The risk of pleural effusion seems to be
highest in infants, but can occur at any age.

Question 25

The MRI shown in this image suggests that the cause of the cervicothoracic syringomyelia in this child is due to:
A. An idiopathic cause
B. Trauma
C. A Chiari malformation
D. Tethered cord due to a cervical dermal sinus
tract
E. A craniocervical ependymoma

Answer 25

C. A Chiari malformation

A syrinx associated with a Chiari 1 malformation
(tonsillar herniation below level of foramen magnum) is treated with posterior fossa decompression

Question 26

What intracranial tumor is associated with poly- cythemia?
A. Ependymoma
B. Pilocytic astrocytoma
C. Medulloblastoma
D. Hemangioblastoma
E. Choriocarcinoma

Answer 26

D. Hemangioblastoma

Hemangioblastomas are grade I tumors; they
are more common in males than in females, and
are associated with Von Hippel–Lindau (VHL) syndrome. Microscopically, these tumors exhibit a
dense network of vascular channels and a large
population of lipid-containing interstitial cells with
nuclear pleomorphism. They are vimentin positive
and EMA negative. Patients with VHL are at risk for
the development of renal cell carcinoma, which interestingly is EMA positive

Question 27

What percentage of children with agenesis of the corpus callosum have developmental delays?
A. 10%
B. 30%
C. 50%
D. 70%
E. 90%

Answer 27

E. 90%

Approximately 90% of patients with agenesis of
the corpus callosum have evidence of developmental delays, and 60% have concomitant seizures.

Question 28

A child presents with a second episode of middle cerebral artery stroke. The cerebral angiogram, shown in this image, suggests:
A. Anterior communicating artery aneurysm
B. Arteriovenous malformation
C. Cavernous malformations
D. Moyamoya disease
E. Vein of Galen malformation

Answer 28

D. Moyamoya disease

Moyamoya disease is a progressive cerebrovascular disorder caused by occluded cerebral arteries,
resulting in recurrent transient ischemic attacks
or strokes. The name moyamoya means “puff of
smoke” in Japanese and describes the angiographic
appearance of this disease: tangled, tiny vessels
formed to compensate for the occlusions.

Question 29

What skull suture is involved in the post-shunting craniosynostosis shown in this image of an 18- month-old toddler?
A. Left coronal suture
B. Sagittal suture
C. Right lambdoid suture
D. Metopic suture
E. Left lambdoid suture

Answer 29

C. Right lambdoid suture

Acquired post-shunt craniosynostosis is a relatively uncommon complication, with over-drainage
in young or premature infants with open fontanelles being the main risk factor. A CT scan with 3D
reconstruction is helpful to diagnose it. Surgical
treatment is required in severe cases with abnormal head shapes.

Question 30

A 9-year-old boy presents with headache, upgaze paresis, and a pineal region tumor. A cerebrospinal fluid analysis is performed showing elevated levels of β-HCG. What tumor type is suspected?
A. Choriocarcinoma
B. Embryonal carcinoma
C. Germinoma
D. Teratoma
E. Yolk sac tumor

Answer 30

A. Choriocarcinoma

Cerebrospinal fluid levels of α-fetoprotein and
β-HCG are most useful for diagnosing yolk sac
tumors and choriocarcinomas, respectively. Levels
also may be used to assess treatment response and
recurrence. (C, D) Pure germinomas and teratomas
usually present with negative markers (α-fetoprotein and β-HCG), although low levels of β-HCG sometimes can be detected.

Question 31

What is the approximate incidence of Chiari 2 mal- formations when a myelomeningocele is present at birth?
A. 100%
B. 75%
C. 50%
D. 25%
E. < 5%

Answer 31

A. 100%

Chiari II malformations are encountered relatively commonly, with an incidence of about
1:1,000 live births. When a child is born with a
myelomeningocele, the vast majority (95 to 100%)
have an associated Chiari II malformation.

Question 32

What is the average head circumference for a new- born and an adult?
A. 29 and 49 cm
B. 31 and 51 cm
C. 33 and 53 cm
D. 35 and 55 cm

Answer 32

D. 35 and 55 cm

Males have slightly larger head circumferences
than females.

Question 33

A newborn girl presents with congestive heart failure. She is noted to have an increased head cir- cumference and dilated scalp veins. Imaging demon- strates a large mass with obstructive hydrocephalus in the area of the posterior third ventricle/pineal region. Your next step in the management of this patient is to:
A. Perform a lumbar puncture
B. Perform an endoscopic third ventriculostomy
with biopsy
C. Plan for surgical resection of the lesion
D. Perform an angiogram
E. Plan for radiation

Answer 33

D. Perform an angiogram

There should be a high suspicion for a vein of
Galen malformation in this scenario. In fact, a vein
of Galen malformation should be considered in
any newborn with heart failure that is not linked
to congenital heart anomaly. An angiogram and
confirmation of this pathology is the next step in
correctly diagnosing and subsequently devising a treatment plan for this etiology. Treatment typically involves a staged endovascular embolization
while treating heart failure with medical agents.
(C) Biopsy or surgical resection of this lesion
potentially would be fatal.

Question 34

Selective dorsal rhizotomy (SDR) classically is con- sidered a surgical treatment for children with spas- ticity. What type of spasticity is best managed by SDR?
A. Spastic diplegia
B. Spastic quadriplegia
C. Mixed spasticity and dystonia
D. Hereditary spastic paraparesis
E. Severe head injury

Answer 34

A. Spastic diplegia

Selective dorsal rhizotomy is suited best for
the treatment of children with primarily lower
extremity spasticity (spastic diplegia). (B–E) These
conditions are managed best with intrathecal
baclofen pump therapy.

Question 35

What genetic condition carries the highest risk of developing intracranial meningiomas in the pedi- atric population?
A. Tuberous sclerosis
B. Sturge-Weber disease
C. Neurofibromatosis type 1
D. Neurofibromatosis type 2
E. von Hippel–Lindau disease

Answer 35

D. Neurofibromatosis type 2

Meningiomas are common primary brain tumors
accounting for up to 25% of all primary brain
tumors, with a peak incidence in the fifth decade
of life. However, meningiomas are rare in the pediatric population, representing less than 5% of all
supratentorial brain tumors in children. Risk factors for developing pediatric meningiomas include prior irradiation or a history of neurofibromatosis type 2. In some series, 50% of pediatric intracranial meningiomas have been associated with these risk factors.

Question 36

Trigonocephaly is caused by premature closure of what skull suture during infancy?
A. Coronal suture
B. Sagittal suture
C. Lambdoid suture
D. Metopic suture
E. Frontosphenoidal suture

Answer 36

D. Metopic suture

In single-suture craniosynostosis, premature closure of the metopic suture results in a triangular
shaped head (trigonocephaly). (A) Premature closure of the coronal suture results in flattening of the
forehead (anterior plagiocephaly or brachycephaly). (B) Premature closure of the sagittal suture results in an elongated and narrow head (scaphocephaly). (C) Premature closure of the lambdoid suture results in flattening at the back of the skull (posterior plagiocephaly).

Question 37

Hypsarrhythmia is an electroencephalographic cha- otic appearance classically seen in children with what condition?
A. Lennox-Gastaut syndrome
B. Infantile spasms
C. Absence seizures
D. Juvenile myoclonic epilepsy
E. Mesial temporal lobe epilepsy

Answer 37

B. Infantile spasms

Infantile spasms (also known as West syndrome) are a form of generalized epilepsy, and they usually begin before the age of 6 months. They commonly are associated with tuberous sclerosis in 20% of cases. The electroencephalogram (EEG) is characteristic, and consists of high-amplitude, irregular, asynchronous, sharp and slow waves with a slowed background rhythm. This gives the EEG a chaotic appearance known as hypsarrhythmia.

Question 38

What fetal spinal anomaly commonly is associated with maternal hyperglycemia?
A. Dandy-Walker malformation
B. Holoprosencephaly
C. Sacral agenesis
D. Encephalocele
E. Chiari malformation

Answer 38

C. Sacral agenesis

Caudal regression syndrome is a generic term
that refers to a continuum of neural tube defects
ranging from coccygeal agenesis to complete agenesis of the entire lumbosacral spine. Sacral agenesis is sporadic, and commonly is associated with
maternal hyperglycemia

Question 39

What supplement during the first trimester of pregnancy is considered preventive for myelo- meningocele?
A. Vitamin A
B. Vitamin B12
C. Vitamin D
D. Zinc
E. Folic acid

Answer 39

E. Folic acid

The U.S. Public Health Service (USPHS) recommends that all women capable of becoming pregnant consume 400 µg of folic acid daily to prevent
neural tube defects (NTDs). Studies have demonstrated that peri-conceptional folic acid supplementation can prevent 50% or more of NTDs, such
as spina bifida and anencephaly. For women who
previously have had an NTD-affected pregnancy,
the Centers for Disease Control and Prevention
(CDC) recommends increasing the intake of folic
acid to 4,000 µg per day beginning at least 1 month
before conception and continuing through the first trimester

Question 40

An endoscope-assisted strip craniectomy procedure for an infant with sagittal craniosynostosis, shown in this image, followed by helmet therapy will have the best cosmetic outcome if it is performed at what age?
A. 18 months
B. 12 months
C. 9 months
D. 6 months
E. 3 months

Answer 40

D. 6 months

Early surgery, preferably in the first 3 months of
life, yields the best outcomes with the endoscope-assisted craniectomy technique for sagittal craniosynostosis. Postcorrection helmet therapy for 12
months is used commonly prescribed

Question 41

What cranial nerves most commonly are affected in a symptomatic Chiari type 2 malformation?
A. VII and VIII
B. V
C. VI
D. XII
E. IX and X

Answer 41

E. IX and X

Symptoms of moderate to severe Chiari 2 malformation commonly include dysfunction of cranial nerves IX and X, which may lead to dysphagia and respiratory distress.

Question 42

According to the Food and Drug Administration (FDA), vagal nerve stimulation is indicated for use in partial-onset seizures refractory to medical ther- apy in patients of what age?
A. Any age
B. Older than 6 years
C. Older than 8 years
D. Older than 12 years
E. Older than 18 years

Answer 42

D. Older than 12 years

Although vagal nerve stimulation (VNS) may
be used “off label” in patients 12 years old and
younger, it is important to counsel patients on the risks and unknowns of doing so. VNS is considered as a palliative treatment for intractable epilepsy

Question 43

What dose of intrathecal baclofen is used during the screening trial prior to pump insertion for chil- dren with spastic quadriplegia?
A. 50 μg
B. 100 μg
C. 200 μg
D. 500 μg
E. 750 μg

Answer 43

A. 50 μg

Intrathecal baclofen at 50 μg generally is used
during the baclofen screening trial. This dose will
cause at least a 1-point decrease in the mean Ashworth score in the lower extremities of children
with spasticity but not with dystonia or athetosis.

Question 44

A 7-year-old boy presents with a skull mass. A skeletal survey, shown in this image, reveals mul-
tiple other bony osteolytic lesions. The most likely 48.
diagnosis of his skull mass is:
A. Dermoid cyst
B. Epidermoid tumor
C. Eosinophilic granuloma
D. Osteoma
E. Ewing sarcoma

Answer 44

C. Eosinophilic granuloma

Eosinophilic granuloma is the most common
type of Langerhans cell histiocytosis. It is characterized by the proliferation of pathogenic Langerhans
cells and cytokine overproduction, and causes inflammation, infiltration, and destruction of many
tissues in the body, most commonly bones.

Question 45

An absolute contraindication to performing an endoscopic third ventriculostomy is:
A. Fourth ventricle outlet obstruction
B. Aqueductal stenosis
C. Presence of intraventricular hemorrhage
D. Patient age younger than 1 year
E. Suspected infection of the cerebrospinal fluid

Answer 45

A. Fourth ventricle outlet obstruction

As cerebrospinal fluid (CSF) is produced by the
choroid plexus in the fourth ventricle and CSF
flows in a rostral-to-caudal fashion, an endoscopic
third ventriculostomy (ETV) would relieve hydrocephalus in the lateral and third ventricles but not
in the fourth ventricle. (B-E) These all represent
relative contraindications and risk factors for ETV failures.

Question 46

The most common intramedullary spinal cord tumor in children is:
A. Ependymoma
B. Hemangioblastoma
C. Astrocytoma
D. Cavernoma
E. Ganglioglioma

Answer 46

C. Astrocytoma

Intrinsic tumors of the spinal cord comprise up
to 55% of all intradural neoplasms in children. The
most common are astrocytomas. In adults, intramedullary ependymomas are the most common
intramedullary spinal cord tumor.

Question 47

At what age does the metopic suture typically close?
A. 1 to 2 months
B. 3 to 9 months
C. 9 to 18 months
D. 24 months
E. 36 months

Answer 47

B. 3 to 9 months

Premature closure of the metopic suture results
in trigonocephaly. (A) The posterior fontanelle typically closes at 1 to 2 months of age. (C) The anterior fontanelle typically closes at 9 and 18 months
of age. (D) The coronal suture fuses at around 24 months of age.

Question 48

Endoscopic third ventriculostomy has the highest success rate in children over the age of 12 months with what pathology?
A. Shunt infection
B. Posterior fossa tumor
C. Myelomeningocele
D. Idiopathic aqueductal stenosis
E. Communicating hydrocephalus

Answer 48

D. Idiopathic aqueductal stenosis

Pediatric patients over 1 year of age with idiopathic aqueductal stenosis are considered the ideal
candidates to receive endoscopic third ventriculostomies. Five-year success rates are 80 to 90%

Question 49

What is the most common pineal region tumor in children?
A. Ependymoma
B. Astrocytoma
C. Germinoma
D. Mature teratoma
E. Meningioma

Answer 49

C. Germinoma

Pineal germ cell tumors are more common than
pineal parenchymal tumors. Germinomas are the
most common pineal region tumors in children,
accounting for up to 60% of intracranial germ cell tumors.

Question 50

A 6-month-old girl has recurrent urinary tract in- fections. Urodynamic studies suggest that she has a neurogenic bladder. MRI of lumbar spine likely will demonstrate what associated pathology?
A. Low-lying conus and fatty filum terminale
B. Arachnoiditis
C. Anterior sacral meningocele
D. Lumbar hemivertebrae
E. Klippel-Feil syndrome

Answer 50

A. Low-lying conus and fatty filum terminale

Tethered cord syndrome should be ruled out as
the cause of newly diagnosed neurogenic hyperreflexic bladder during childhood, even in the presence of the conus medullaris in a normal position

Question 51

The majority of spinal neurenteric cysts are found in what location?
A. Anterior to the spinal cord and extradural
B. Posterior to the spinal cord and extradural
C. Intradural and extramedullary
D. Intradural and intramedullary
E. Craniocervical junction

Answer 51

C. Intradural and extramedullary

Neurenteric cysts more commonly occur intraspinal (90% of cases) than intracranial (10% of
cases), and they usually present in the first or second decades of life. The majority of spinal neurenteric cysts are intradural and extramedullary, and
they typically occur at the cervicothoracic junction or near the conus medullaris.

Question 52

Patients with split cord malformation type 1 have what anatomy?
A. Two hemicords in one dural sac
B. Two hemicords in two separate dural sacs
C. Open myelomeningocele
D. Anterior sacral meningocele
E. Thoracic dermal sinus tract

Answer 52

B. Two hemicords in two separate dural sacs

Split cord malformation (SCM) is a new term
used for diastematomyelia and diplomyelia. SCMs are a form of occult spinal dysraphism, which is defined as a skin-covered lesion that has no exposed neural tissues and no visible cystic masses. SCMs are of two types: type 1 consists of two hemicords, each contained within its own dural tube and separated by a median bony spur, whereas type 2 consists of two hemicords housed in a single dural tube separated by a fibrous median septum.

Question 53

A 6-year-old boy presents to the emergency depart- ment after a motor vehicle collision. He denies pain and weakness and has an unremarkable neu- rologic exam. Lateral X-rays identify 3 mm of C2 on C3 anterolisthesis with angulation. What is the next step in the management of this patient?
A. Flexion-extension X-rays of the cervical spine if there are no other cervical spine injuries or fractures
B. Hard orthosis for suspected Effendi type 1 hangman fracture
C. MRI to evaluate for ligamentous injury
D. Surgical reduction and stabilization for sus-
pected Effendi type 2 hangman fracture
E. Closed reduction with craniocervical traction

Answer 53

A. Flexion-extension X-rays of the cervical spine if there are no other cervical spine injuries or fractures

Pseudosubluxation of C2 on C3 is common in
children up to 10 years old due to ligamentous laxity. This finding often is seen on X-rays showing
slight flexion, which often will reduce in a neutral
or extended position. If a line is drawn between
the spinolaminar junctions of C1 to C3 (the Swischuk line), the anterior C2 spinous process should be within 2 mm of this line. Anything beyond 2 mm is suggestive of pathological subluxation. Lack of soft tissue swelling also would be consistent with pseudosubluxation.

Question 54

What initial weakness develops during the infec- tious neuropathy associated with diphtheria?
A. Visual accommodation paralysis
B. Facial paralysis
C. Oropharyngeal paralysis
D. Distal sensorimotor polyneuropathy
E. Ascending paralysis

Answer 54

A. Visual accommodation paralysis

A symmetric neuropathy develops in 20% of patients who become infected with diphtheria (Corynebacterium diphtheriae). Patients initially develop
visual accommodation (ciliary) paralysis followed
by facial and oropharyngeal paralysis. Typically,
there is preservation of extraocular movements. Distal sensorimotor polyneuropathy then follows in the fifth to eighth week of illness and results in
mild to severe ascending paralysis.

Question 55

A 6-year-old boy presents with new-onset seizures. MRI of the brain, shown in this image, demon- strates an enhancing temporal mass. What is the most likely diagnosis?
A. Anaplastic astrocytoma
B. Ependymoma
C. Ganglioglioma
D. Meningioma
E. Primitive neuroectodermal tumor

Answer 55

C. Ganglioglioma

Gangliogliomas are WHO grade 1 circumscribed tumors that often have a solid, mural, contrast-enhancing nodule with a small cystic component.
These lesions often are located in the temporal
lobe, and they usually present with epilepsy in
children of 5 to 6 years of age.

Question 56

What is the most common complication during re- section of a lipomyelomeningocele during infancy?
A. Neural injury
B. Aseptic meningitis
C. Cerebrospinal fluid leak and infection
D. Neurogenic bladder
E. Hydrocephalus

Answer 56

C. Cerebrospinal fluid leak and infection

The single most common complication of lipomyelomeningocele resection and de-tethering of
the spinal cord is cerebrospinal fluid leak and
subsequent infection. This complication occurs
in less than 15% of patients in most series. A
watertight dural closure and careful postoperative patient positioning are critical steps to reduce this complication.

Question 57

Pediatric patients with ventricular shunt catheters
are at risk for developing ventriculitis. What bacteria most commonly are associated with shunt
infections?
A. Staphylococcus epidermidis
B. Staphylococcus aureus
C. Streptococcus pneumoniae
D. Streptococcus milleri
E. Escherichia coli

Answer 57

A. Staphylococcus epidermidis

Pediatric patients with ventricular shunt catheters are at risk of developing ventriculitis, which
most commonly is caused by infections with Staphylococcus epidermidis. In ventriculitis, the ventricles become covered by a prominent exudate, and
the inflammatory infiltrates extend into the adjacent periventricular white matter