Pathology of Stroke

Question 1

What vessels supply the cerebral cortex?

Answer 1

Internal Carotid Arteries [70%]
Vertebral Arteries [30%]
Both through circle of willis

Question 2

Define Cerebral Perfusion Pressure

Answer 2

the difference between systemic arterial blood pressure and intracranial pressure

Question 3

What causes Global cerebral ischemia?

Answer 3

results from a fall in cerebral perfusion pressure below threshold for autoregulation

Question 4

What causes local cerebral ischemia?

Answer 4

arterial stenosis or occlusion

Question 5

What cell in the CNS is most vulnerable to ischemia?

Answer 5

Neurons [pyramidal neurons in hippocampus, Purkinje cells in cerebellum]

Question 6

What areas of the brain are vulnerable to hypotension or cardiac arrest?

Answer 6

Watershed areas, Cerebral cortex, Hippocampus

Question 7

Describe the microscopic appearance of acute neuronal injury in Purkinje cells

Answer 7

deep eosinophilia of cytoplasm and variable degrees of nuclear disintegration

Question 8

Describe the microscopic appearance of chronic neuronal injury

Answer 8

Neuronal loss and Gliosis [+ edema and demyelination]

Question 9

Define TIA

Answer 9

term used to describe if symptoms resolve within 24 hours

Question 10

Define stroke

Answer 10

an “abrupt onset” of focal or global neurological symptoms caused by ischemia or hemorrhage lasting more than 24 hours

Question 11

What is the most common cause of cerebral infarction?

Answer 11

Atherosclerosis

Question 12

General epidemiology of stroke

Answer 12

> 70% - cerebral infarction
~ 20% – cerebral hemorrhage
remainder is subarachnoid hemorrhage

Question 13

What is the 3rd most common cause of mortality in the US?

Answer 13

Strokes

Question 14

What are risk factors for strokes?

Answer 14

HTN
Lipids
DM
Environmental factors
Obesity
Impaired Cardiac function
Oral contraceptive with high estrogen content
Anti-phospholipis Abs

Question 15

What risk factor account for 50% of hemorrhagic strokes?

Answer 15

Hypertension

Question 16

Why is hyperlipidemia considered a risk factor and what does it affect?

Answer 16

Atheroma

carotid arteries > vertebral arteries > circle of willis

Question 17

What is the link between DM and Strokes?

Answer 17

DM increases incidence of strokes unto 3-folds in both sexes

Question 18

What environmental factors increased the risk for strokes?

Answer 18

Diets resulting in hyperlipidemia
High salt intake may promote HTN
Smoking

Question 19

Which cardiac condition increases the risk of stroke and why?

Answer 19

A. Fib
increased risk of embolisation

Question 20

How does Anti-phospholipid autoantibodies increase risks of strokes?

Answer 20

Associated with recurrent thrombosis

Two most relevant antibodies are anticardiolipin and lupus anticoagulant.

Thrombotic stroke and transient ischaemic attacks

Question 21

Stroke

Answer 21

Ischemic
Hemorrhagic [intracerebral or subarachnoid hemorrhage]

Question 22

Pathophysiology of Global Ischemic stroke

Answer 22

Global generalized hypoxic encephalopathy

Hypotension : Acute MI. Heart failure. Shock

Question 23

Pathophysiology of Focal Ischemic stroke

Answer 23

cerebral infarcts.
Thrombosis: underlying atherosclerosis.
Emboli.

Question 24

Describe the acute morphology of ischemic stroke

Answer 24

edema neuronal microvacuolization  pyknosis  karyorrhexis  neutrophils

Question 25

Describe the chronic morphology of ischemic stroke

Answer 25

macrophagesgliosis

Question 26

In order, list the histopathologic progression of CNS ischemic infarcts

Answer 26

Edema ''red neurons" polymorphonuclear leukocytosis monocytes [macrophages] Gliosis

Question 27

What type of stroke [embolic, hemorrhagic, thrombotic] hast the fastest onset?

Answer 27

Embolic stroke

Question 28

What condition causes an emboli from the heart?

Answer 28

from left atrium in AFib Endocarditis Cardiac surgery prosthetic or damaged valves (rheumatic fever, calcific aortic valve disease)

Question 29

What are four possible causes of emboli?

Answer 29

Atheromatous plaques (carotid arteries) The heart fat emboli Gas

Question 30

Describe gas as a possible source of emboli

Answer 30

Air or nitrogen as emboli seen in decompression sickness

Question 31

Describe fat as a possible source of emboli

Answer 31

Fat emboli as a result of trauma [stained with Oil-red O]

Question 32

What type of stroke is associated with Fat emboli?

Answer 32

multiple petechial haemorrhages in the grey and white matter

Question 33

What structures are common affected by intracerebral hemorrhage?

Answer 33

Basal Ganglia, Cerebellum

Question 34

What is the leading cause of intracerebral hemorrhage?

Answer 34

HTN

Question 35

What is the prognosis of intracerebral hemorrhage?

Answer 35

Lethal conditions but the hematoma can slowly be resorbed over months with from restitution of function

Question 36

What are causes of Subarachnoid hemorrhage?

Answer 36

Rupture of Congenital [Berry Aneurysmd] Atherosclerotic and mycotic aneurysms AV malformation

Question 37

What is the prognosis of Berry Aneurysms?

Answer 37

Mortality is high. Re-bleeding is common in survivors. Resorption of blood may lead to meningeal fibrosis & hydrocephalus

Question 38

What increases the likeness of a berry aneurysms to "rupture" ?

Answer 38

probability increases with size of aneurysm + incidence acutely increases in intracranial pressure [straining at stoll, sex]

Question 39

What arteries are commonly implicated in Berry Aneurysm?

Answer 39

Question 40

What types of strokes are associated with Hypertension?

Answer 40

Intracerebral hemorrhage Lacunar infarcts [basal ganglia]

Question 41

What is the clinical significance of Lacunar Infarcts?

Answer 41

can be silent or cause serious impairment

Question 42

What arteries are implicated in lacunar infacrts?

Answer 42

lenticulostriate arteries of internal capsule, Putamen, thalamus, pontine tegmentum, cerebellum.

Question 43

Describe the gross morphology of lacunar infarcts

Answer 43

Small often cystic infarcts

Question 44

What is a common site of hemorrhage in hypertensive patients?

Answer 44

Basal Ganglia