Rob cards

Question 1

Genetics of GBM

Answer 1

1) EGFR amplification/mutation indicates primary GBM
2) Tumor protein 53 most common mutated gene in GBM
3) IDH1 and IDH2 mutations are good prognostic indicators
4) MGMT promoter methylation results in improved response to alkalating agents like TMZ

Question 2

Enhancing lesions

Answer 2

Metastases
Toxo ----> check HIV
Lymphoma
MS
Glioma
Infection

Question 3

MS workup and treatment

Answer 3

Workup

• CSF sent for cell count, glucose, protein, culture, PCR for HSV/VZV, EBV, CMV
• CSF sent for oligoclonal bands, myelin basic protein (MBP), IgG index
• Serum neuromyelitis optica (NMO) and myelin oligodendrocyte glycoprotein (MOG) antibodies.
• Serum HIV test

Treatment
- IV Methylprednisone 1000mg daily x5 days

Question 4

Nerve Transfer for postop C5 palsy

Answer 4

Spinal accessory to suprascapular nerve transfer to reanimate supraspinatous and infraspinatous

Branch of the radial nerve from triceps to the axillary nerve to reinnervate the deltoid

Ulnar branch to musculocutaneous branch to help with biceps

Question 5

SRS dosing

Answer 5

24 grey single fraction for 1cm
18 grey for 2cm
14-15 grey for 3cm or bigger

AVM: 24 grey

Acoustics-12-16 grey single fraction

Question 6

Barbiturate coma

Answer 6

Pentobarbital 10mg/kg load over 30 minutes THEN 5 mg/kg/hr x3 doses THEN 1mg/kg/hr

Question 7

Devic syndrome

Answer 7

Same thing as NMO
Variant of MS with acute bilateral optic neuritis and transverse myelitis (extending over 3 levels).
Spinal cord edema can be so severe as to cause complete blockade
Less chance of recovery compared to MS
Serum IgG antibodies (NMO-IgG) help differentiate from MS

Question 8

Schilling Test

Answer 8

Determines cause of B12 deficiency even if B12 injections have already been given
Radiolabeled cyanobalamin is given orally, followed by a parenteral flushing dose of nonradioactive vitamin, and the percentage of radioactivity is measured in the urine over 24 hours

Question 9

Pheochromocytoma Labs

Answer 9

1) Fractionated plasma metanephrines
2) 24 hr urine collection of total cathecholamines and metanephrines
3) When elevation is found, clonidine suppression test can be done. With a pheo, no change noted with clonidine

Question 10

MRI appearance of arachnoid vs epidermoid vs dermoid

Answer 10

Arachnoid cyst: same intensity as CSF on all MRI sequences
Epidermoid cyst: high signal on DWI differentiates from arachnoid cyst
Dermoid cyst: high intensity on T1 similar to fat

Question 11

Foramen Magnum lesions notable presenting symptoms

Answer 11

“Rotating paralysis”: weakness usually ipsilateral UE —> ipsilateral LE —–> contralateral LE —–> contralateral UE
Aching neck pain with head movement
Long tract signs (hyperreflexia and spasticity)

Question 12

Pituitary Labs

Answer 12

TSH, Free T4, Prolactin, FSH, LH, Cortisol, ACTH, IGF-1, GH, Testosterone

Question 13

Diagnosis of DI

Answer 13

Urine output >250cc/hr x 3 hours
Serum Na >145
Urine spec grav <1.005

Also, urine/plasma osmolality ratio <1

Question 14

MRI perfusion for recurrent GBM

Answer 14

Cerebral blood volume!!!
>2.6 mL blood/gram of tissue = tumor
<0.6 mL blood/gram of tissue = radiation necrosis

Question 15

Air embolus signs

Answer 15

Drop in end tidal CO2
Increase in end tidal nitrogen and PaCO2
Hypotension, tachycardia (like hypovolemia), cardiac arrryhtmias

Question 16

Air embolus treatment

Answer 16

Reverse Trend position
Apply gentle compression over sinus with sheets of thrombin soaked Gelfoam and large Cottonoid pads.
Flood field with saline
Pack wound with saline-soaked sponges
Wax bone edges
Inspect for large rent

Anesthesiologist: 
Turn off nitrous oxide
Give 100% oxygen
Aspirate air from central line
Give volume
Consider left lateral decub position

Question 17

Hyponatremia eval

Answer 17

• Serum osmolality, Urine osmolality, Urine sodium
• Urine sodium low —> sodium depletion suspected. ex- diuretics, vomiting, diarrhea, ascites, NG tube
• Urine sodium high, poor renal function —> pathologic sodium loss in urine. ex- chronic renal failure
• Urine sodium high, good renal function—> SIADH or cerebral salt wasting

SIADH: intravascular volume increased
-Treatment: volume restriction; less than 1L 24 hours + Na tabs
CSW: intravascular volume decreased
-Treatment: colloid infusion with Albumisol