CVD and Ischemia

Question 1

Blood vessels involved in

Anterior Circulation

Answer 1

internal carotid, anterior cerebral, middle cerebral, ophthalmic arteries

Question 2

Blood vessels involved in

Posterior Circulation

Answer 2

vertebral, basilar, posterior cerebral arteries (and their branches)

Question 3

Define

Focal neurological deficit

Answer 3

A deficit that is associated with a specific area of dysfunction/lesion. Examples include: hemi/quadrant anopia, loss of tactile sensation for part of the body, UMN deficits for part of the body, Broca or Wernicke aphasia.

Question 4

Pathological stages of plaque formation in atherosclerosis

Answer 4

Deposition of fat in the intima of vessels – macrophages migrate into area and secrete cytokines to initiate an inflammatory reaction – smooth muscle cells proliferate and connective tissue is deposited – plaque continues to grow in size

Question 5

What are the pathophysiologic stages of occlusion in small vessels?

Answer 5

Lipohyalinosis involves endothelial damage followed by thickening of the vessel wall. This can cause vessel occlusion or formation of microaneurysms.

Question 6

What are risk factors for lipohyalinosis?

Answer 6

Hypertension, diabetes, aging are major risk factors.

Question 7

What vessels are involved in lipohyalinosis

Answer 7

Long, narrow vessels such as lenticulostriates, thalamic perforators, and basilar branches

Question 8

What is a lacunar stroke?

Answer 8

Lacunar strokes are infarcts of small, penetrating blood vessels that result in small lesions deep in the brain.

Question 9

Where do lacunar strokes occur?

Answer 9

They occur along long, narrow penetrating vessels that supply regions such as basal ganglia, internal capsule, diencephalon.

Question 10

What process contributes to lacunar strokes?

Answer 10

Lipohyalinosis contributes to infarcts of these vessels affected by hypertension, diabetes, and age.

Question 11

What is a TIA?

Answer 11

A temporary decrease in blood flow to part of the brain lasting typically about 5 minutes. It may be caused by an embolism that eventually dissolves or a thrombosis.

Question 12

How can SAH be distinguished from meningitis?

Answer 12

SAH does not involve fever and would show RBCs in an LP. CT/MRI may also be helpful to show blood in sulcal spaces vs meningeal inflammation.

Question 13

Pathological process in

Thombosis

Answer 13

Atherosclerosis – fat deposition, fibrosis, occlusion

Question 14

Pathologic Process in

Small Vessel Occlusion/ Lacunar Infarct

Answer 14

Lipohyalinosis – endothelial damage, vessel thickening, occlusion

Question 15

Pathologic process in

Embolism

Answer 15

Dislodged objects circulating in bloodstream

Question 16

Pathologic Process in

Arterial Dissection

Answer 16

Separation of intima and media layers with expanding hematoma

Question 17

Risk factors in

Thrombosis

Answer 17

Hypertension, diabetes, hyperlipidemia, smoking, inflammation

Question 18

Risk factors in

Small Vessel Occlusion/ Lacunar Infarct

Answer 18

Hypertension, diabetes, aging

Question 19

Risk factors in

Embolism

Answer 19

Common sources: Heart and internal carotid artery

Question 20

Risk factors in

Arterial Dissection

Answer 20

Hypertension, trauma, atherosclerosis

Question 21

Treatment for

Thrombosis

Answer 21

tPA, thrombectomy

Question 22

Treatment for

Small Vessel Occlusion/ Lacunar Infarct

Answer 22

Control hypertension

Question 23

Treatment for

Embolism

Answer 23

Anticoagulants, AF control

Question 24

Treatment for

Arterial Dissection

Answer 24

thrombectomy

Question 25

3 criteria for brain death

Answer 25

lack of brain function, lack of cranial nerve function, and loss of all brainstem reflexes

Question 26

What is the caloric test?

Answer 26

involves infusion of cold/warm water into the external ear canal that stimulates movement of endolymph and thereby elicits the vestibulo-ocular reflex

Question 27

Why is the caloric test used to test brain death?

Answer 27

assesses function of a large portion of the brainstem from medulla to midbrain that contains the pathway for this response

Question 28

What reflexes do we test to assess brainstem function?

Answer 28

Pupillary light reflex Corneal reflex Oculo-cephalic

Question 29

What does the pupillary light reflex test?

Answer 29

Midbrain function

Question 30

What does the corneal reflex test?

Answer 30

Pons function

Question 31

What does the oculo-cephalic reflex or caloric test assess?

Answer 31

Medulla function

Question 32

# Location of Intracerebral Hemorrhage (aneurysm, AVM)

Answer 32

Subcortical – basal ganglia, thalamus, brainstem, cerebellum

Question 33

# Location of Subarachnoid Hemorrhage

Answer 33

Subarachnoid space

Question 34

# Location of Berry or fusiform aneurysm

Answer 34

Circle of Willis, vessel branch locations Any location

Question 35

# Location of AVM

Answer 35

Subcortical or subarachnoid

Question 36

# Risk factors for Intracerebral hemorrhage

Answer 36

Hypertension causing microaneurysms, AVM, trauma, tumor

Question 37

# Risk factors for Subarachnoid hemorrhage

Answer 37

Trauma Aneurysm

Question 38

# Treatments for Aneurysms

Answer 38

Clipping/ Coiling

Question 39

# Treatments for AVM

Answer 39

BP control

Question 40

# Treatment of Intracerebral Hemorrhage

Answer 40

BP control

Question 41

# Treatment for Subarachnoid hemorrhage

Answer 41

BP control

Question 42

# Symptoms of Intracerebral Hemorrhage

Answer 42

Focal signs, headache, nausea, confusion

Question 43

# Symptoms of Subarachnoid hemorrhage

Answer 43

Worst headache ever, stiff neck

Question 44

What is the first step in evaluating a patient with symptoms of stroke and what methods can be used to assess it?

Answer 44

The first step is to determine whether the stroke resulted from hemorrhage or infarct. Methods to assess this involve non-contrast CT (first choice), LP, CT/MRI angiography.

Question 45

How are hemorrhagic strokes treated?

Answer 45

Hemorrhagic strokes are treated by controlling blood pressure. Aneurysms can be clipped or coiled.

Question 46

What are some complications of these strokes?

Answer 46

Hemorrhage can result in hydrocephalus if ventricular blockage occurs and cerebral vasospasm due to irritability of blood, which can be treated with nimodipine.

Question 47

How does cerebral blood flow respond to changes in systemic arterial pressure?

Answer 47

CBF remains constant from 50 – 150 mmHg of systemic arterial pressure. This ensures that the brain, which utilizes 20% of the energy output of the body, has adequate supply of O2 and glucose to function normally

Question 48

# Explain Excitotoxicity

Answer 48

Excitotoxicity occurs from exposure to low O2 levels/ischemia

Question 49

# Explain How ischemia causes excitotoxicity

Answer 49

Excitotoxicity occurs from exposure to low O2 levels/ischemia. Under this condition, oxidative metabolism is reduced and glycolysis is insufficient to produce enough ATP to maintain the Na/K pump. As a result, intracellular Na levels rise, cytotoxic edema occurs, electrical activity eventually ceases, the neurons depolarize, and glutamate is released from terminals. Glutamate binds to AMPA and NMDA postsynaptic receptors allowing prolonged Ca++ entry into neurons. The wave of intracellular Ca++ activates degradative proteins and free radicals.

Question 50

In which CNS locations are neurons most sensitive to ischemia ?

Answer 50

Hippocampus, cerebellum, cortex