Ischemic stroke

Question 1

Definition of ischemic stroke

Answer 1

Ischemic injury to the brain causing a persistent clinical deficit at 24 hours. Even mild residual deficits are classified as strokes. The severity of the deficit is not the determinant, only that the deficit is present at 24 hours.

Question 2

Definition of TIA

Answer 2

Transient Ischemic Attack: ischemic neurological deficits that have completely resolved by 24 hours, regardless of their severity or relative duration (seconds or hours).

Question 3

Presentation of a large-vessel ischemic stroke

Answer 3

Large vessel ischemia causes deficits in multiple systems.

Ex.: large vessel ischemic stroke in the middle cerebral artery territory will have a hemiparesis, a hemi-sensory loss, and a homonymous hemi-anopsia contralateral to the ischemic side of the brain.

This type of stroke requires a large vessel mechanism causing partial or complete occlusion of a major artery.

Question 4

Presentation of small-vessel ischemic stroke

Answer 4

An isolated motor (or isolated sensory) deficit on one side of the body

Caused by occlusion (atheromatous, lipohyalinosis) of the small penetrating vessels that arise from large arteries deep into the brain.

Question 5

Multi-infarct dementia

Answer 5

Small vessel ischemic strokes that cause lacunar infarctions and contribute to the stepwise process of multi-infarct dementia, from multiple lacunar strokes that can accumulate over many years

Question 6

Traditional non-modifiable atherosclerosis risk factors for stroke

Answer 6

Age, men, race (white people less)

Question 7

Traditional modifiable atherosclerosis risk factors for stroke

Answer 7

HTN, lipid disorders, homocysteine elevation (treatable with folate, vit b12, and vit B6), smoking, obesity, physical inactivity, diabetes, alcohol abuse

Question 8

Structural risks for stroke

Answer 8

Cardiac abnormalities
Arterial Stenosis, Dissection, Occlusion
Infectious endocarditis
Atrial myxoma (cardiac tumor)

Question 9

Less Common Mechanisms of Stroke (“Young Stroke” mechanisms)

Answer 9

1. The Vasculopathies: (Fibromuscular Dysplasia (FMD), Moya-Moya, Arterial Dissection)
2. Hematological Disorders: (Deficiencies of Protein C, Protein S, or Antithrombin, or the presence of Factor V Leiden, or Prothrombin Gene, Malignancies, Sickle cell anemia, Hyperviscosity States, oral contraceptive use, Antiphospholipid antibodies
3. Inflammatory: (Vasculitis, migraine)
4. Venous infarction
5. Vasospasm

Question 10

Reducing risk of stroke

Answer 10

Treat all risk factors possible

“good health” approach (sleep, eat healthy, exercise, fitness, low stress, high happiness) as well as specific dietary, vitamin and medication therapies where needed.

Plus antithrombotic agent

Question 11

Single agents that reduce the long term risk of recurrent ischemic stroke

Answer 11

Aspirin, Thienopyridines (Clopidogrel, Prasurgrel, Ticlopidine) and Anticoagulants

Question 12

Use of anticoagulants after stroke

Answer 12

Warfarin is highly effective in primary prevention of stroke with atrial fibrillation or mechanical heart valves.

Injected/Intravenous Anticoagulants are commonly used in the hospital setting and for short term (i.e. trays to weeks) needs (heparin).

Question 13

What is the surgical therapy for symptomatic patients with high grade (70-90%) stenosis

Answer 13

Endarterectomy (highly beneficial)

Question 14

Emergency management of stroke

Answer 14

Don’t lower bp
Give fluids
TPA (thrombolytic agent) if 0-4.5 hr
Only give glucose if pt is hypoglycemic

Question 15

Lumbar puncture and stroke

Answer 15

Useful to exclude neurosyphilis, vasculitis, other inflammatory conditons, and the occasional stroke mimic.. Otherwise, it is not a routine part of the evaluation of ischemic stroke. Perhaps the greatest utility of lumbar puncture is in the determination of subarachnoid hemorrhage, which can occur with a normal CT scan in two situations.

Question 16

Acute prophylaxis for stroke

Answer 16

ASA and heparin (controversial)

Heparin is only considered to prevent recurrent embolization or progression of large vessel syndromes in patients with a high recurrence risk. Second, delaying the institution of anticoagulation for 48 hours (the high risk period for hemorrhagic CNS catastrophes) and repeating the CT scan, will still reduce the bulk of the re-embolization risk for a few days to a week. Delaying makes sense in larger strokes, which are more susceptible to secondary hemorrhage.

Question 17

Symptoms of stroke in the different arteries

Answer 17

Anterior cerebral- legs (leg weakness)
Middle cerebral artery- weakness in one side of arm and face; aphasia;
Posterior cerebral artery- vision; visual inputs and sensation
Ataxia- cerebellar signs
Basilar stroke- worst kind of stroke to have (coma and death)

Question 18

Stroke in cortex

Answer 18

Motor + sensory findings in similar distribution
Motor findings variable 
Aphasia
Cognitive issues
Apraxia
Visual field deficits
Gerstmann’s syndrome
Higher level sensory processing

Question 19

Subcortical stroke

Answer 19

Face + arm + leg symmetrically
Acute onset movement disorders
Common syndromes:
Clumsy hand dysarthria
Ataxia hemiparesis
Pure motor hemiparesis
Hemi sensory loss
Mixed sensory-motor