Nervous System

Question 1

Extra axial well circumscribed dural based mass partially calcified.

Dx and consequences.

Answer 1

Meningioma - B9, but may have HA, seizure, focal neuro defects dt mass effect.

Question 2

Head elevation, sedation, IV mannitol, hyperventialion, removal of CSF - all are interventions for____

Answer 2

lowers ICP

Question 3

lowering ICP:

what does head elevation do?

Answer 3

increases cerebral outflow from brain

Question 4

lowering ICP:

what does sedation do?

Answer 4

lowers metabolic demand and controls HTN

Question 5

lowering ICP:

what does IV mannitol do?

Answer 5

ostomotic diuresis - decreases free water in brain tissue

Question 6

lowering ICP:

what does short term hyperventilation do?

Answer 6

decreases paCO2, causing cerebral vasoconstriction and decreasing ICP.

(CO2 is a much more important regulator of cerebral blood flow than O2)

Question 7

innervation of anterior thigh compartment (knee E and hip F; sensation to ant thigh and medial leg)

Answer 7

femoral nerve

Question 8

innervation of medial thigh compartment (thigh adduction; sensation to medial thigh)

Answer 8

obturator nerve

Question 9

innervation of posterior thigh compartment (knee flexion, foot plantar flexion; sensation to all of leg except medial)

Answer 9

tibial nerve

Question 10

brief loss of consciousness followed by lucid interval. hematoma expansion leads to decreased consciousness and increased ICP

Answer 10

epidural hematoma. trauma to sphenoid and tearing of MMA

lens-shaped (biconvex) on CT. does not cross suture lines

Question 11

HA nad confusion over 1-2 days

Answer 11

subdural hematoma. tearing of bridging veins.

crescent on CT

Question 12

hypertension, bradycardia, respiratory depression

Answer 12

cushing’s reflex - indicates increased ICP.

Question 13

ipsilateral hemiparesis, ipsilateral mydriasis and strabismus, contralateral hemianopsia, altered mentation

Answer 13

transtentorial herniation of parahippocampal uncus

Question 14

name neruo deficits expected in an uncal/transtentorial herniation - CN3 deficit

Answer 14

loss of PSNS =

• early: mydriasis
• late: ptosis and down/out gaze of ipsilateral pupil dt unopposed trochlear (CN4) and abducent (CN6)

Question 15

UE sensory deficit and weakness mo-years after trauma (i.e. whiplash) - dx and etiology

Answer 15

syringomyelia.

enlargement of spinal cord due to CSF retention - damage to STT (pain/temp) and UE motor fibers (medial location in CST)

Question 16

Firm, nontender swelling on right cheek of 36y M. similar presentation 2y ago - dx as tumor and removed.

dx? repeat surgery @ risk for…?

Answer 16

dx - parotid neoplasm

facial nerve at risk. *unilateral facial droop

Question 17

hypoglossal nerve function

Answer 17

tongue

Question 18

recurrent laryngeal branch of vagus nerve. vulnerable during what surgery?

Answer 18

hoarseness

para/thyroid surgery