80. Stroke

Question 1

What is the more common type of stroke?

What is a TIA?

Answer 1

Ischemic (85%) > Hemorrhagic (15%)

TIA: transient stroke sx (<24 hrs), no infarct/changes on MRI/CT
RF: high age (>60yo), HTN, DM

Question 2

What are the 5 etiologies of ischemic stroke?

Answer 2

1. Atherothrombotic (large artery to brain)
2. Cardioembolic (clot from heart)
3. Lacunar (small brain artery)
4. Infrequent (2/2 disease/infection)
5. Cryptogenic (unknown)

Question 3

Difference between PWI and DWI for stroke

Answer 3

Ischemic Core: dead, infarcted tissue
Penumbra: salvageable brain tissue, will infarct w/o tx

DWI: shows infarcted tissue
PWI: shows hypoxic tissue
(difference between PWI/DWI is salvageable penumbra)

Malignant Profile: reperfusion injury

Question 4

What are the two main acute tx of ischemic stroke?

Answer 4

1. tPA - give <4.5hrs of onset
2. Intraarterial catheter based method for ICA/MCA/BA - extended window for small-core /large-penumbra strokes (use 6-24hrs of onset)

Question 5

How can MRI differentiate between embolic and small vessel thrombotic stroke?

Answer 5

Embolic: infarcts in 2 different vascular territories

Thrombotic: infarct in one location (lacunar stroke - atherosclerotic)

Question 6

What are the stroke syndromes for the following occlusions?
L. ACA
L. MCA
R. PCA
L. Retinal Artery

Answer 6

L. ACA = R leg hemiparesis/anesthesia, difficulty initiating verbal response (premotor areas)

L. MCA = R arm/face hemiparesis/anesthesia, global aphasia (Broca’s and Wernicke’s)

R. PCA = Left visual field homonymous vision loss

L Retinal Artery = Left eye painless vision loss (amaurosis fugax)

Question 7

What are the stroke syndromes for occlusion of:

• Lacunar A.
• BA Penetrators
• R PICA

Answer 7

Lacunar: damage to sub cortical tracts (no cortical sx)

• R. Internal Capsule (Post Limb) = pure motor hemoparesis
• or pure sensory loss
• or ataxic hemiparesis
• or clumsy hand dysarthria

BA penetrators: Crossed Findings
- L. hemiparesis and R hemiataxia (Dysarthria too)

R PICA: R ataxia (R cerebellum), HA, Nausea/Vomiting (Area Postrema), Dizziness

Question 8

Major site of spontaneous ICH

Answer 8

PUTAMEN (then lobar subcortical - MCA/PCA/ACA)

Question 9

What are the 4 key causes of ICH?

Answer 9

1. HTN
2. Aneurysm Rupture
3. Vascular Malformation
4. CAA - cerebral amyloid angiography: lobar hemorrhage in old (>65yo) demented, non-HTN pts - multiple spontaneous ICH (fragile vessels)