Cases

Question 1

Diagnostic criteria of NF2?

Answer 1

1. Bilateral VS
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

Most common surgical approaches for vestibular schwannomas?

Answer 2

1. Retrosigmoid.
2. Translab.
3. Middle fossa.

Question 3

Outcomes for radiosurgery for vestibular scwhannomas?

Answer 3

1. 81% tumor control rate at 15 years with hearing preservation rates of 73% at 1 year and 48% at 5 years.

Question 4

Genetics of tuberous sclerosis?

Answer 4

1. TSC is an autosomal dominant disorder.
2. Caused by mutation in tumor suppressor
   genes TSC1 (located on 9q) or TSC2 (located
   on 16p).
3. The protein products of these genes are: Hamartin (TSC1) and Tuberin (TSC2).

Question 5

Common indications for hemispherotomy?

Answer 5

1. Hemimegalencephaly
2. Sturge–Weber syndrome
3. Rasmussen encephalitis
4. Encephalomalacia (traumatic, ischemia)
5. Porencephaly
6. Cortical dysplasia
7. Migration disorders
8. Hemiplegia–hemiconvulsion–epilepsy syndrome

Question 6

DDx of cerebellar lesions?

Answer 6

1. Hemangioblastoma.
2. Metastasis.
3. Medulloblastoma.
4. Pilocytic astrocytoma.
5. Less likely: abscess, glioblastoma, brainstem glioma, cavernous angioma, cerebellar liponeurocytoma, hemorrhage, infarction.

Question 7

Simpson grading scale for meningiomas

Answer 7

Grade I: macroscopically complete removal with excision of dural attachment and abnormal bone (including sinus resection when involved)
Grade II: macroscopically complete resection with endothermy coagulation (cautery or laser) of dural attachment
3Grade III: macroscopically complete tumor resec- tion without resection or coagulation of dural attachment or of its extradural extensions (e.g., hyperostotic bone)
Grade IV: partial removal leaving tumor in situ
Grade V: simple decompression (± biopsy)

Question 8

Classification for meningioma invasion into the SSS?

Answer 8

Type I: lesion attachment to the outer layer of the sinus wall
Type II: tumor fragment inside the lateral recess
Type III: invasion of the ipsilateral wall
Type IV: invasion of the lateral wall and roof
Types V and VI: complete sinus occlusion, without or
with invasion of the contralateral wall, respectively

Question 9

Clinical differences between olfactory groove meningiomas and tuberculum sellae meningiomas?

Answer 9

Clinically, these tumors may be differentiated from olfactory groove meningiomas since tuberculum sellae meningiomas initially present with visual dysfunction and as they grow larger, they can affect olfaction; whereas olfactory groove meningiomas usually present with disturbances in olfaction and as they enlarge posteriorly, they may affect vision.

Question 10

Features of Foster-Kennedy syndrome?

Answer 10

Classically described with olfactory groove meningiomas.

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

Question 11

Differences between OGM and tuberculum sellae meningomas in respect to the optic chiasm.

Answer 11

The main feature distinguishing olfactory groove meningiomas and tuberculum sellae meningiomas is the location of the chiasm. The optic nerves and chiasm are located inferolateral to the tumor in olfactory groove meningiomas but are located superolateral to the tumor in tuberculum sellae meningiomas.

Question 12

Classifications of sphenoid wing meningiomas?

Answer 12

1. Lateral or pterional.
2. Middle.
3. Medial or clinoidal.

Question 13

Blood supply to lateral sphenoid wing meningiomas?

Answer 13

1. STA, MMA, and anterior meningeal artery.

Question 14

Blood supply to middle sphenoid wing meningiomas?

Answer 14

1. Branches of ethmoid arteries.

Question 15

Blood supply to medial sphenoid wing meningiomas?

Answer 15

1. Ascending branch of pharyngeal artery.

2. Recurrent branch of the ophthalmic artery via superior orbital fissure.