CM: Aspects of Vascular Dz

Question 1

What are the two different kinds of strokes?

Answer 1

ischemic - artery occluded

hemorrhagic - artery ruptures

Question 2

What is ACA territory often spared during ICA strokes?

Answer 2

because of communicating arteries

Question 3

What main symptoms are seen in left MCA stroke vs. right?

Answer 3

left - aphasia

right - apraxia and/or sensory neglect

Question 4

What do the deep branches of the MCA supply and what are symptoms of a stroke there?

Answer 4

basal ganglia, capsules, thalamus

contralateral hemiplagia of face, arm, and leg, sometimes with hemianesthesia

Question 5

What structures are possibly affected by an ACA stroke?

Answer 5

medial portions of frontal and parietal, corpus callosum, sometimes caudate and internal capsule

Question 6

What are the symptoms of an ACA stroke?

Answer 6

contralateral hemiplagia (esp leg - fibers more medial), grasp reflex, urinary incontinence
bilateral occlusion may cause spastic paraparesis, emotional disturbances, apathy, confusion, mutism

Question 7

What structures are possibly affected by a PCA stroke?

Answer 7

occipital, splenium of CC, thalamus, midbrain

Question 8

What are some symptoms of PCA strokes and why are they variable?

Answer 8

vision loss, thalamic injury, Weber’s syndrome (contralateral weakness and CN III involvement - oculomotor paresis and dilated pupil)
because of collateral and fetal circulation

Question 9

What are TIAs?

Answer 9

temporary interruption of blood flow –> transient neurological dysfunction (<24 hrs)
w/o acute infarction
1/2 will have stroke, lots w/i 48 hrs

Question 10

What are the five ischemic stroke subtypes defined by the TOAST criterion?

Answer 10

large vessel dz - atherosclerosis, most common
small vessel dz - lacunar strokes, penetrating artery dz
cardiogenic embolism
stroke from other determined cause
stroke from undetermined cause

Question 11

By what two mechanisms can plaques cause ischemic strokes in large vessel dz?

Answer 11

flow reduction from stenosis or occlusion (when diameter reduced by ~70%) - near bifurcations
artery to artery embolism from ulcerated, thrombogenic surfaces - nonstenotic plaques can create platelet plugs that thrombose or embolize

Question 12

What are the symptoms of small vessel dz strokes?

Answer 12

pure motor or pure sensory strokes involving face, arm, and leg simultaneously
can be debilitating and tend to recur
injury around lateral ventricles & subcortical white

Question 13

Why are cardiogenic emboli strokes so easy to prevent?

Answer 13

cardiac symptoms usually present first and antithrombotic therapies very effective

Question 14

What are the three key elements in diagnosing stroke due to cardiogenic embolism?

Answer 14

abrupt onset, cortical neurologic deficit, potential cardiac source

Question 15

What are some other causes of strokes in young people?

Answer 15

hypercoagulable state, cocaine, neurosyphilis in HIV+

Question 16

What are the main risk factors for ischemic stroke?

Answer 16

HTN, age and gender (after 55), smoking, diabetes, elevated cholesterol

Question 17

What are the most common causes of CNS hemorrhages leading to hemorrhagic stroke?

Answer 17

HTN, aneurysm, subdural hematomas, AV malformations, amyloid angiopathy

Question 18

What are hypertensive bleeds?

Answer 18

ruptures of small penetrating arteries –> hematoma in subcortical, pons, cerebellum, typically 55-75, VERY high BP on presentation
puts at risk for both types of stroke

Question 19

What diagnostic studies can be done for further evaluation of pts with a stroke?

Answer 19

bloodwork - serum glucose and electrolytes, renal function, CBC, PT, INR, PTT (further testing for inf, inflammation, hypercoagulability deferred unless strong suspicion)
Cardiac studies - ECG, Echo
imaging - CT, CTA, MRI, MRA
Angiography - determines etiology after diagnosed by other means, gold standard, can intervene

Question 20

What is the ischemic penumbra?

Answer 20

around area of necrosis - hypoperfused, hypometabolic,electrically silent tissue that has marginally sufficient flow to keep neuron alive
goal of acute stroke management is to salvage it

Question 21

What are options for acute stroke treatment?

Answer 21

recombinant TPA - stimulates clot breakdown, only if symptoms <4.5 hrs, NIHSS demonstrates deficit, CT does not show bleeding or non-stroke cause of symptoms, main risk = bleeding, control elevated BP after
aspirin 160-300mg w/i 48 hrs, LMWH

Question 22

What are contraindications for TPA?

Answer 22

seizure at onset of stroke, recent surgery/stroke, extreme uncontrollable elevations of BP, coagulopathy

Question 23

What are established therapies that reduce the risk of stroke?

Answer 23

antiplatelet agents (aspirin, clopidogrel) - longterm
warfarin - not for initial, use in A fib
dabigatran - thrombin inhibitor, for A fib
Carotid endarterectomy (CEA) & Carotid angioplasty and stenting (CAS)

Question 24

What pts can benefit from CEA?

Answer 24

symptomatic pts w TIA or stroke w/i past 6 mos (best w/i 2 wks) who had ipsilateral carotid stenosis of >70%
stenosis of 50-69% depends on pt factors

Question 25

When is CAS maybe a better alternative than CEA?

Answer 25

symptomatic pts at avg or low risk of complications and stenosis >70%, lesions difficult to assess surgically