Case Review Questions

Question 1

What are the diagnostic criteria for NF-2?

Answer 1

1. Bilateral vestibular schwannoma.
2. Family history of NF-2 (first degree relative) plus unilateral VS.
3. Family history of NF-2 plus two of the following: meningioma, schwannoma (nonvestibular), glioma, neurofibroma, juvenile posterior subcapsular lenticular cataract, or opacity.

Question 2

What is the 50/50 rule for serviceable hearing?

Answer 2

1. A pure tone (PTA) showing values of < 50 dB and speech discrimination with recognition of > 50% indicate serviceable hearing.

Question 3

Differential diagnosis for intraventricular lesions?

Answer 3

CENTRAL MS

1. Choroid plexus papilloma or carcinoma, colloid cyst, central neurocytoma, cavernoma.
2. Ependymoma, epidermoid/dermoid.
3. Neurocytoma.
4. Teratoma, tuber.
5. “Rule out” infection.
6. Astrocytoma, AVM, aneurysm, abscess.
7. Lipoma, lymphoma.
8. Mets, meningioma.
9. Subependymoma, SEGA.

Question 4

Which neurocutaneous syndrome is associated with SEGAs?

Answer 4

1. Tuberous sclerosis.

Question 5

What are some complications that can be seen with transcallosal approaches to the lateral ventricles?

Answer 5

1. Weakness.
2. Akinetic mutism.
3. Memory deficits.

Question 6

Which vein does the thalamostriate vein empty into?

Answer 6

1. Internal cerebral vein.

Question 7

What are some findings associated with Sturge-Weber?

Answer 7

1. Port wine stain (usually affecting V1).
2. Leptomeningeal angiomas.
3. Seizures.
4. Hemiparesis.
5. MR or learning disability.
6. Glaucoma.

Question 8

What are some indications for hemispherectomy?

Answer 8

1. Intractable epilepsy with unilateral hemisphere damage.
2. Congenital hemiplegia.
3. Chronic encephalitis.
4. Hemimegalencephaly.
5. Sturge-Weber syndrome.

Question 9

What lab abnormality can be seen with hemangioblastomas?

Answer 9

1. Polycythemia.

Question 10

Genetic mutation seen in NF-1?

Answer 10

1. NF1 gene mutation on chrom. 17.

Question 11

Genetic mutation seen in NF-2?

Answer 11

1. NF2 gene mutation on chrom. 22.

Question 12

Genetic mutation seen in tuberous sclerosis?

Answer 12

1. TSC1 and TSC2 gene mutations on chrom. 9 and 16.

Question 13

Genetic mutation seen in VHL?

Answer 13

1. VHL gene mutation on chrom. 3P.

Question 14

What are the 3 main types of spinal AVMs?

Answer 14

1. Dural AV fistula.
2. Perimedullary fistula.
3. Intramedullary AVMs.

Question 15

Pathophysiology of dural AV fistulas.

Answer 15

1. Lesion consists of a small AV fistula within or just beneath the dura at the point where a feeding radicular artery enters the dura at the nerve root sleeve.

Question 16

How do dural AV fistulas cause neurologic deficits?

Answer 16

1. AV fistulas are low flow lesions resulting in venous hypertension and decreased spinal cord perfusion.

Question 17

Pathophysiology of perimedullary fistulas.

Answer 17

1. Located intradurally but in the extramedullary space.

2. Characterized by a single shunt without a nidus.

Question 18

Indications to operate on GSWs to the head?

Answer 18

1. Favorable GCS.
2. Debridement of devitalized tissue or bone fragments.
3. Evacuation of hematomas.
4. Separation of intracranial component from air sinuses.

Question 19

Contraindications for surgery in GSWs to the head?

Answer 19

1. Bullet traveling across the midline.
2. Bullet traveling across ventricles.
3. Bullets traveling across more than one contiguous lobe of the brain.

Question 20

Symptoms of Foster-Kennedy syndrome.

Answer 20

1. Anosmia.
2. Unilateral optic atrophy.
3. Contralateral papilledema.

Question 21

What are the main features distinguishing olfactory groove meningiomas from tuberculum sellae meningiomas.

Answer 21

1. The location of the chiasm.
2. The optic nerves and optic chiasm are located inferolateral to the tumor with olfactory groove meningiomas.
3. The optic nerves and chiasm are located superolateral to the tumor in tuberculum sellae meningiomas.

Question 22

Describe Chiari type 1.

Answer 22

1. Shallow posterior fossa.
2. Tonsillar descent down to the level of C1-C2 junction.
3. Posterior compression of the cervical spinal cord.

Question 23

Describe Chiari type 2.

Answer 23

1. Shallow posterior fossa.
2. Descent of the cerebellar hemispheres, vermis and tonsils to the upper cervical spinal cord.
3. Posterior compression of the brainstem and cervical spinal cord.

Question 24

Describe Chiari type 3.

Answer 24

1. Shallow posterior fossa.
2. Tonsillar herniation.
3. Brainstem and cervical spinal cord compression.
4. Occipital encephalocele.

Question 25

Location and function of the principal sensory nucleus of CN V.

Answer 25

1. Located in the upper pons. | 2. Conveys tactile and pressure senses from the face.

Question 26

Location and function of the mesencephalic nucleus of CN V.

Answer 26

1. Located near the central gray matter of the upper 4th ventricle. 2. Conveys pressure and kinesthetic senses from the teeth, hard palate, and jaw.

Question 27

Location and function of the spinal trigeminal nucleus of CN V.

Answer 27

1. Extends from the upper cervical spine to the midpons. 2. Divided into 3 parts (pars caudalis, pars interpolaris, and pars oralis) which convey sensation of pain and temperature from different parts of the face.

Question 28

Function of the motor nucleus of CN V.

Answer 28

1. Relays fibers to the muscles of mastication and plays part in the jaw jerk reflex.

Question 29

Which vessel is the most common culprit of in trigeminal neuralgia?

Answer 29

1. Superior cerebellar artery.

Question 30

What is the definition of moyamoya disease?

Answer 30

1. Progressive occlusion of terminal ICAs, ACAs or MCAs. | 2. Profuse lenticulostriate collateral formation (moyamoya vessels) at the base of the brain.

Question 31

Clinical presentations of moyamoya in children?

Answer 31

1. Ischemic symptoms in 80%. 2. Epilepsy in 5%. 3. ICH in 2.5%. 4. Other symptoms in 12.5% (headache, movement disorders, or mix of symptoms).

Question 32

What are some factors associated with moyamoya?

Answer 32

1. Asian ethnicity. 2. NF-1. 3. Radiation for optic or hypothalamic pathway gliomas. 4. Down syndrome. 5. Renal artery stenosis. 6. Thalassemia and sickle cell anemia.

Question 33

Direct revascularization procedures for moyamoya?

Answer 33

1. Superficial temporal artery to MCA bypass.

Question 34

Indirect revascularization procedures for moyamoya?

Answer 34

1. EDAS: encephaloduroarterosynagniosis. 2. EMS: encephalomyosynangiosis. 3. EDAMS: encephaloduraarteriomyosynangiosis. 4. Modified EDAS (pial synangiosis).

Question 35

Why are vagal nerve stimulators contraindicated ont he right vagal nerve?

Answer 35

1. The right vagal nerve innervates the SA node in more than 60% and stimulation will result in asystole.

Question 36

What are common side effects of vagal nerve stimulators?

Answer 36

1. Cough. 2. Hoarseness. 3. Throat pain.