Pathology of Cerebrovascular Disease

Question 1

Define the following terms:

• Hypoxia
• Anoxia
• Ischemia
• Stroke

Answer 1

• Hypoxia: oxygen deprivation
• Anoxia: COMPLETE oxygen deprivation
• Ischemia: inadequate blood flow
• Stroke: a clinical term describing loss of brain function to to vascular disturbance in brain either due to ischemia or hemorrhage

Question 2

What are some neuronal populations that are particularly susceptible to anoxia/ischemia?

Answer 2

Watershed areas

CA1 sector of hippocampus

Purkinje cells of cerebellum

Question 3

Time progression of infarct?

Answer 3

> 12 hours - nothing distinct on gross exam

4-12 hours - red pkynotic neurons (shrinking nuclei)

48-72 hours (2-3 days) - can observe something grossly; cellular/neutrophilic infiltrates

> 1 week - can observe more evident necrosis grossly; macrophages clean up

Months-years - hole because brain does not regenerate; cystic degeneration surrounded by gliosis

Question 4

Compare non-hemorrhagic vs. hemorrhagic infarcts.

Answer 4

Non-hemorrhagic make up most of infarcts. No blood observed grossly, usually single vessel territory involvement. Etiology usually thrombotic occlusion (esp atherosclerotic).

Hemorrhagic infarct see blood on gross exam and usually involves multiple vessel areas, especially at grey/white junctions. Etiology is usually embolic, reason being emboli tends to break down and allow blood back into dead tissue.

Question 5

Lacunar infarct

Definition
Imaging and gross exam

Answer 5

Small infarct due to HTN (arteriosclerosis).

Note that hemorrhage can cause both lacunar infarct intraparenchymal hemorrhage.

On both imaging and gross examination, looks like various little holes.

Question 6

Etiology of subdural hematoma?

Answer 6

Due to VENOUS bleeding from bridging veins going from cortex to venous sinuses.

Slow progression.

“Flat” crescent profile that is stopped my falx at midline. Dura remains attached, as opposed to epidural bleed where it gets “peeled” off skull.

Question 7

Symptoms of subarachnoid bleeds?

Answer 7

“worst headache of my life”

Meningitic symptoms

Progressive mental alteration

Question 8

Saccular aneurysms

Treatment?

Answer 8

Weak points at the circle of willis (branches) that balloon out

Often acomms

Treat by clipping or coil

Question 9

How does gross exam differ for lacunar infarct vs. intraparenchymal hemorrhage?

Answer 9

Lacunar infarct has evidence of petechial hemorrhage while intraparenchymal hemorrhage from HTN shows LARGE bleeds/clots.

Question 10

If an elderly person had intraparenchymal hemorrahge due to amyloid angiopathy, what is a likely cause?

Answer 10

Alzheimer’s

Question 11

How do intraparenchymal hemorrhages localize differently if it was due to HTN vs. amyloid?

Answer 11

HTN - more deep and central

Amyloid - more peripheral in white matter

Question 12

Transtentorial (uncal) hernation

Answer 12

Like other herniations, potential result of edema.

Uncus swell and pushes down on mibraid, leading to herniation of midbrain. Can impinge on CN III to cause visual defects.

Question 13

Tonsillar herniation

Answer 13

Cerebellum is edematous and expands to “wrap” around brainstem.

Medulla becomes pushed on –> respiratory/cardiac centers located there so this becomes dangerous situation and can turn fatal

Question 14

Central herniation

Answer 14

Whole brain pushes down on pons –> puts pressure on small vessels (esp lenticulostriate vessels) to cause duret hemorrhage

Duret hemorrhage is central pontine hemorrhage and result is FATAL

Question 15

Cingulate herniation

Answer 15

Common and local vascular compression only

Least clinically relevant