Pediatric Neurosurgery

14Pediatric Neurosurgery

1.

E Mammillary bodies, as shown in this image.

image

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.

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.

4.

D Dermoid tumor

Congenital dermal sinus tracts are a type of closed spinal dysraphism in which an epitheliumlined 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

17.

C Obstructive hydrocephalus secondary to aqueductal stenosis

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Jul 18, 2016 | Posted by in NEUROSURGERY | Comments Off on Pediatric Neurosurgery

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