Ischemic & Hemorrhagic Stroke

Question 1

Fibromuscular Dysplasia (FMD)

Answer 1

Hypertrophy of arterial media causing multiple areas of segmental stenosis; characterstically involves renal, carotid, and/or vertebral arteries and is associated with arterial dissection and intracranial saccular aneurysms

Rare cause of ischemic stroke, primarily affects women in 30s-40s

Question 2

Moya-Moya

Answer 2

Non-atherosclerotic focal occlusion of the middle cerebral artery due to intimal hyperplasia; also associated with saccular aneurysms and dissection

Rare cause of ischemic stroke, primarily affects women in their 30s-40s

Question 3

Arterial dissection

Answer 3

Tear in the endothelial lining that allows blood to dissect between the endothelium and the adventitia, within the media; causes “flap” occlusion, and/or may result in emboli which occlude the artery downstream

Question 4

Hematological disorders associated with ischemic stroke

Answer 4

Protein C/S deficiency
Anti-thrombin deficiency 
Factor V Leiden 
Malignancies 
Sickle Cell Anemia 
Elevated hematocrit (>60%)
Thrombocytosis (>1,000,000) 
Oral contraceptives 
Antiphospholipid antibodies

Question 5

Non-modifiable risk factors - Stroke

Answer 5

Age
Gender
Family History
Race?

Question 6

Structural Risk Factors - Ischemic Stroke

Answer 6

Atrial fibrillation 
CHF 
Infectious endocarditis 
ASD/PFO 
Cardiac Tumors (Atrial Myxoma) 
Arterial stenosis 
Arterial dissection

Question 7

Modifiable risk factors - Ischeic Stroke

Answer 7

Hypertension 
Lipid abnormalities - high total/LDL, low HDL 
Homocysteine elevation 
Smoking
Obesity
Physical inactivity
Diabetes
Alcohol abuse

Question 8

Use of anti-platelet agents in ischemic stroke

Answer 8

Aspirin - 81mg or 325mg / day

Clopidogrel

Dipyridamole

Question 9

Use of anticoagulation in ischemic stroke

Answer 9

Warfarin - primary prevention of stroke in patients with atrial fibrillation, mechanical heart valves, previous hx of embolization, HTN, heart failure

Direct thrombin inhibitors (Dabigatran, Rivaroxiban, Apixaban) - stroke prevention in lower risk patients

Heparin / LMWH - IV, used in the acute hospital setting

Question 10

Indication for carotid endarterectomy

Answer 10

Benefit > risk in patients iwth > 60% carotid stenosis, even if asymptomatic

Question 11

Subdural hemorrhage - etiology

Answer 11

Occurs between the dura and arachnoid layer; typically from a torn bridging vein between the dura and the cortex; blood collects slowly in a “crescent” shape - may be asymptomatic, enlarging over days to months

Question 12

Epidural hemorrhage - etiology

Answer 12

Occurs between the skull and dura; typically an arterial bleed caused by laceration of the middle meningeal artery; blood collects in a “lens” shaped hematoma

Question 13

Subarachnoid hemorrhage - etiology

Answer 13

Occurs underneath the arachnoid layer, next to the brain; may occur secondary to trauma or spontaneously secondary to aneurysm or AVM

Question 14

Subarachnoid hemorrhage - presentation

Answer 14

Cataclysmic onset, “worst headache of my life”

Sudden death occurs in 1/3 due to acute hydrocephalus or sympathetic surge and cardiac arrhythmia

Cranial Nerve (III) Palsy

Question 15

Intraparenchymal hemorrhage - etiology and presentation

Answer 15

Blood clots which dissect into the brain, typically in the deep grey matter (putamen, thalamus, pons, cerebellum); associated with chronic hypertension

Presents as mild headache + deficit, progressing over minutes to hours with decreasing level of consciousness; may present as hemiparesis progressing to hemiplegia

Question 16

Lobar hemorrhages

Answer 16

Atypical, intraparenchymal hemorrhage occurring within the deep white matter; more often caused by AVM, aneurysm, vasculitis, bleeding disorder

Question 17

Amyloid angiopathy

Answer 17

Recurrent lobar hemorrhages leading to progressive dementia; amyloid deposition is found within the vessels

Question 18

Arteriovenous malformation (AVM)

Answer 18

Congenital malformation of the resistance arterioles causing high pressure arterial blood to burst into thin-walled capillaries; cause of 2% of all intracranial hemorrhages

Question 19

Risk factors for aneurysm rupture

Answer 19

Age
Prior hemorrhage
Deep location

*Size doesn’t matter much for rupture risk; matters a lot for treatment

Question 20

Grading of subarachnoid hemorrhage

Answer 20

Grade 1 - asymptomatic or minimal headache; slight nuchal rigidity

Grade 2 - moderate to severe headache with nuchal rigidity; no neurological deficit other than cranial nerve palsy

Grade 3 - drowsiness, confusion, mild focal deficit

Grade 4 - stupor, moderate to severe hemiparesis

Grade 5 - deep coma, decerebrate posturing

Question 21

Location of subaracnoid hemorrhage

Answer 21

Anterior communicating artery (40%)

Middle cerebral artery - at carotid bifurcation (20%) or trifurcation branch point (35%)

Basilar artery (4%)

Base of brain bleeds are more likely sporadic in etiology; bleeds in “area of convexity” (cerebral hemispheres, temporal poles) more likely traumatic

Question 22

Hemorrhagic infarction

Answer 22

Occurs as a result of reperfusion of dead tissue following spontaneous or iatrogenic clot lysis, with leakage of blood from the damaged parenchymal vessel into the surrounding tissue

Usually due to embolism