Neuro

Question 1

Cause of death in SAH

Answer 1

#1 = initial bleed
#2 = rebleed (usually w/in 24 hours)

Vasospasm = 3-10days

Question 2

Na 145
Serum Osm 295
Low Urine OSM

Answer 2

DI

- DDAVP when urine output >350-400ml/hr

Question 3

HypoNa
Hypovolemic
Serum Osm <280
Urine Na >20

Answer 3

Cerebral salt wasting
Tx = volume replacement

Serum Na 120, hypo-osmolar hypovolemic hyponatremia

Question 4

HypoNa
Euvolemic
Serum Osm <280
Urine Na >20

Answer 4

SIADH

• FeNa >1%
• Urine Osm >100->300
• Causes: TCAs, Thiazides, oral hypoglycemics

Also low serum uric acid

Question 5

Pathway for MEPs

Answer 5

Superior –> Inferior
Limb cortex –> internal capsule –> brainstem –> corticospinal tract –> peripheral nerve

MEPs are affected the MOST by volatiles

Question 6

Nerves to block for awake CEA

Answer 6

C2-4
Block both superficial (easy) and deep cervical plexus block (harder)
Roots lie in a lie between Chassagniac tubercle to mastoid process

Question 7

How does CO2 affect cerebral blood flow

Answer 7

Inc CO2 —> inc CBF 1-2ml/100g/min

Steep from 25-75mmHg

Oxygen curve only steep at PAO2 < 50 which inc CBF

Question 8

Most likely cause of CRAO

Answer 8

Direct pressure on the eyes

• unilateral
• cherry red spot on macula
• visual acuity does not improve

Question 9

Painless visual loss, non-reactive pupil, no light perception, normal optic disc

Answer 9

PION

Question 10

Cerebral blood flow level where ischemia is seen on EEG

Answer 10

15-20ml/min/100mg

Question 11

Cerebral vessel lesion with crossed signs like right face and left leg weakness

Answer 11

Basilar artery/brainstem lesion