Stoke Pathology N29

Question 1

CVA

Answer 1

cerebrovascular accident or stroke, non-convulsive focal neurological deficit

Question 2

Risk Factors for CVA

Answer 2

Advanced age, “stroke belt” SE US, genetic predisposition, male, black (hypertension)

Question 3

Hypertension, high cholesterol, diabetes, smoking alter

Answer 3

vessel walls: decrease the production of NO by epithelial cells and increase local mediation of vessel tone = atherosclerosis

Question 4

Result of alteration in blood vessel walls:

Answer 4

thombosis, embolism, inflammation, vasoconstriction, vascular remodeling

Question 5

Ischemic Stroke (80%)

Answer 5

insufficient blood supply to meet metabolic demands

Question 6

Types of ischemic strokes

Answer 6

Focal ischemia: occlusion of a specific vessel

Global ischemia: drastic reduction in systemic BP

Question 7

Causes of ischemic strokes

Answer 7

Thrombosis (localized occlusion), embolism (dislodged thrombosis), Hypoperfusion (heart failure)

Question 8

Hemorrhagic Stroke (20%, but 3x as lethal)

Answer 8

accumulation of blood due to ruptured vessels

Question 9

Types of Hemorrhagic strokes

Answer 9

Intra-axial (within the brain) or extra-axial ( within the skull, outside the brain)

Question 10

Types of Intra-axial hemorrhagic strokes

Answer 10

Intra-parenchymal: bleeding within the brain tissue

Intra-ventricular: bleeding within the ventricles

Question 11

Types of Extra-axial hemorrhagic strokes

Answer 11

Epidural: bleeding between dura mater and skull
Subdural: between dura and arachnoid mater
Subarachnoid: between arachnoid and pia mater

Question 12

Cerebral Blood Flow regulation

Answer 12

blood vessel diameter can become blocked and therefor CBF to area diminishes

Question 13

Ischemia causes

Answer 13

decline in ATP, glucose, and pH also in apparent diffusion coefficient in ECS (tissue swelling)

Question 14

Normal CBF

Answer 14

50-60

Question 15

Oligemia

Answer 15

20-40

Question 16

Ischemia

Answer 16

<20

Question 17

During ischemia, electrical function becomes impaired

Answer 17

<20

Question 18

During ischemia, cell death occurs

Answer 18

> 10

Question 19

Core infarct occurs when

Answer 19

CBF is >10 and cell death occurs due to ischemia (localized O2 deprivation)

Question 20

Penumbra

Answer 20

Within 1 hr, an area surrounding the core infarct is under oligemia conditions

Question 21

Core Infarct is determined by levels of

Answer 21

decreased ATP

Question 22

Penumbra is determined by levels of

Answer 22

decreased pH

Question 23

Window of Opportunity

Answer 23

2-4 hours following infarct if the viable penumbra is reperfused, ischemia can be reversed

Question 24

Ischemia-induced neuronal cell death may spread

Answer 24

from the infarct and into the penumbra

Question 25

Mechanisms of ischemia-induced neuronal cell death

Answer 25

Glutamate excitotoxicity, peri-infarct or spreading depolarization, Calcium homeostasis disruption

Question 26

Glutamate excitotoxicity (primary)

Answer 26

depleted energy stores --> release of glutamate-->NMDA and AMPA-->influx of Na and Ca--> excitation/excitotoxicity

Question 27

Peri-infarct or spreading depolarization (secondary)

Answer 27

Infarct cell death --> release of glutamate and K penumbra --> repetitive depolarization/repolarization causing cell death

Question 28

Calcium Homeostasis disruption (delayed)

Answer 28

Ca influx causes activation of destructive enzymes --> inflammation

Question 29

Necrosis

Answer 29

Compaction and rupturing of cell contents causing inflammation

Question 30

Apoptosis

Answer 30

programmed cell death, membrane intact, not associated with inflammation (requires ATP)

Question 31

Edema

Answer 31

increases intra-cranial pressure (secondary damage)

Question 32

Vasogenic Edema

Answer 32

increased ECF due to BBB defect

Question 33

Cytotoxic edema

Answer 33

swelling or neurons and glia due to failure to transport Na and Ca

Question 34

Inflammation

Answer 34

tissue injury--> inflammatory mediators--> vasodilation, vasoconstriction, increased permeability, and platelet aggregation

Question 35

Histologically you may not see the demarcation between ___________ and

Answer 35

gray and white matter due to loss of structural integrity mediated by proteases Fluid-filled cysts: result of macrophage removal

Question 36

Glutamate receptor antagonist

Answer 36

reduce spreading of depolarizations to reduce infarct size (ADVERSE effects cause neurotoxicity)

Question 37

Calcium Channel Inhibitors

Answer 37

Reduce infarct size (no benefit to stroke patient)

Question 38

Free Radical Scavengers

Answer 38

increase intracellular GLUTATHIONE levels

Question 39

Clot dissolvers

Answer 39

Tissue plasminogen activator (thrombolytic) but must be administered with 4.5 hours of stroke

Question 40

Anticoagulants

Answer 40

partially prevent stoke

Question 41

Antiplatelet agents

Answer 41

prevent platelet aggregation and clot formation (some preventative to stroke)