Cerebrovascular Disease

Question 1

What are the three general things that can go wrong in cerebrovascular disease?

Answer 1

thombosis
embolism
hemorrhage
(stroke applies to all of these)

Question 2

What is the difference between a thrombosis and embolism?

Answer 2

thrombosis develops in place.

embolism develops elsewhere and then travels to the brain where it gets lodged

Question 3

What is global cerebral ischemia caused by?

Answer 3

hypotension

Question 4

What does the outcome of global cerebral ischemia depend on?

Answer 4

the severity of the hypotension and the amount of time

Question 5

a severe global cerebral ischemia will result in what?

Answer 5

mild will just be transient confusion

severe will be persistent vegetative state of brain death

Question 6

What are the infarcts called in global cerebral ischemia?

Answer 6

watershed infarcts

Question 7

What will the brain look like on gross pathology after global ischemia?

Answer 7

thinned cortex, loss of brain mass - brain just starts to autolyse and there’s very little distinctionb etween gray and white matter

Question 8

What will you see on histology the first day after global ischemia?

Answer 8

red neurons and neutrophils

Question 9

After the first day of global ischemia what will you see on histology?

Answer 9

necrosis, macrophages, vascular proliferation and gliosis

eventually you’ll lose the necrotic tissue

Question 10

What areas are particularly susceptible to hypoxia in global ischemia?

Answer 10

watershed areas - located at the spots where the main cerebral arteries join - so the ACA/MCA watershed and the PCA/MCA watershed

Question 11

What is laminar necrosis?

Answer 11

It occurs during global ischemia - a thin band of necrosis with noraml brain tissue underneath and a small layer of normal tissue above as well

Question 12

Why is the layer of cortex above the laminar necrosis normal?

Answer 12

it’s supplied by vessels in the meninges

Question 13

Focal cerebral ischemia is due to what?

Answer 13

obstruction of blood flow

Question 14

What are the two types of focal cerebral infarcts?

Answer 14

ischemic (pale) infarcts

Hemorrhagic (red) infarcts

Question 15

What are pale infarcts due to?

Answer 15

usually due to thrombi arising from atherosclerotic plaques int he carotid arteries

Question 16

What are red infarcts caused by

Answer 16

usually due to emboli - they stick to the walls and damage the vessels, then when it’s broken up and reperfusion takes place, the damaged vessel ruptures and you get hemorrhage

Question 17

Where do emboli usually come from

Answer 17

the heart that’s not beating properly

Question 18

What diagnosis is usually a harbinger of future focal cerebral iscemia?

Answer 18

TIAs

Question 19

Where are the most common locations for thrombosis to develop in the brain

Answer 19

1. carotid bifurcation
2. MCA origin
3. Ends of basilar artery

Question 20

Besides blood clot, what can form an embolism?

Answer 20

Fat and bone marrow from a bad fracture

Question 21

Where do emboli usually stick in the brain?

Answer 21

MCA branch points - leading to hemorrhagic infarction

Question 22

What will infarcts eventually form with time?

Answer 22

cavitations

Question 23

What are the early microscopic changes of a focal infarct?

Answer 23

12 hours - red neurons, edema, swollen astrocytes
12-48 hours: lots of neutrophils
2-3 days: more macrophages

Question 24

What are the later changes of focal infarcts (1 week, 2, weeks, post 2 weeks)

Answer 24

1 week: gliosis begins
2 weeks: even more macrophages
after 2 weeks: dense gliosis and new capillaries

Question 25

What infarcts are particuliarly associated with hypertension?

Answer 25

lacunar infarcts

Question 26

Where do lacunar infarcts occur in the brain generally?

Answer 26

in the deep white matter - especialy the basal ganglia

Question 27

Besides lacunar infarcts, what pathology can be seen with hypertension in the brain?

Answer 27

slip hemorrhages - caused by rupture of little penetrating vessels
over time the hemorrhages resorb leaving a brownish slit-like cavity

Question 28

What will you see microscopically with slit hemorrhages?

Answer 28

hemosiderin-laden macrophages and gliosis

Question 29

What is acute hypertensive encephalopathy?

Answer 29

it’s malignant hypertension - swollen brain with greatly increased intracranial pressure

Question 30

what are the symptoms of acute hypertensive encephalopathy?

Answer 30

confusion, convulsions, coma

Question 31

What pathology will the brain have with acute hypertensive encephalopathy?

Answer 31

it will be swollen with petechiae and fibrinoid necrosis of arterioles

Question 32

What does fibrinoid necrosis of arteriols mean?

Answer 32

it means you just have a vessels with necrotic walls - due to the high rpessure over time (peopke used to think it looked fibrous, hence the name)

Question 33

Intracranial hemorrhage in the subdural or epidural space is usually ____
Heomrrhage in parnchyma or subarachnoid is usually from _____

Answer 33

trauma

underlying cerebrovascular disease

Question 34

Parenchymal hemorrhage is usually from a rupture of small intraparenchymal vessle related to what chronic disease

Answer 34

hypertension

Question 35

What are the two general categories of parenchymal hemorrhage? (hint: location)

Answer 35

ganglionic (near the basal ganglia)

lobar (more in the cortex)

Question 36

What sorts of microaneurysms can often be seen in hypertension due to the weakness of the vessel walls?

Answer 36

charcot-bouchard microaneurysms

Question 37

Where do charcot-bouchard microaneurysms usually form?

Answer 37

along the deep penetrating arteries deep in the brain, but really all over

Question 38

A subarachnoid hemorrhage is usually from rupture of what?

Answer 38

a berry aneurysm

Question 39

At what size do you really start to worry about a berry aneurysm?

Answer 39

at 1 cm or bigger - they have a 50% chance of bleeding within a year

Question 40

If the patient survives a subarachnoid hemorrhage, what are they at further risk for?

Answer 40

vasospastic injury (venous spasm, decreasing perfusion oddly enough)
communicating hydrocephalus (as hemorrhage resorbs leaving fibrin blocking the resorption)