Lecture 15 The Pathology of Cerebro-vascular Disease

Question 1

Describe the venous drainage of the brain

Answer 1

• Veins do not accompany arteries

* Large venous sinuses within dura

Question 2

Define ischaemia

Answer 2

Lack of blood flow

Question 3

Define Hypoxia

Answer 3

Lack of oxygen

Question 4

Define a Stroke (WHO)

Answer 4

Focal neurological deficit (loss of function affecting a specific region of the central nervous system) due to disruption of blood supply

Question 5

Cause of a stroke

Answer 5

Interruption of supply of oxygen and nutrients, causing damage to brain tissue

Question 6

Interruption of supply of oxygen caused by changes in:

Answer 6

o Vessel wall
o Blood flow (including blood pressure)
o Blood constituents

Question 7

In practice 3 main causes of localised interrupted blood supply are

Answer 7

1. Atheroma + thrombosis of artery causing ischaemia
2. Thromboembolism (for example, from left atrium) causing ischaemia
3. Ruptured aneurysm of a cerebral vessel causing haemorrhage

Question 8

Whats a common place for atheroma and thrombosis in the circle of Willis

Answer 8

Internal carotid artery thrombosis – typically get ischaemia in middle cerebral artery territory (but can affect elsewhere)

Question 9

Describe transient symptoms of ischaemia

Answer 9

Transient symptoms (<24 hours) – due to reversible ischaemia(transient ischaemic attack) = tissue still viable

Question 10

Describe longstanding symptoms of Ischaemia

Answer 10

Longstanding symptoms (>24 hours)– due to irreversible ischaemia causing localised brain death = infarct

Question 11

Define regional cerebral infart

Answer 11

Localised area of brain death

Question 12

What would you see grossly in an area of regional cerebral infarct

Answer 12

Congested vessels
Tissue degeneration
Yellow coloration
Swelling around the brain tissue

Question 13

Describe the histology of infarct tissue of the brain

Answer 13

Loss of neurones - causes clinical functional deficit
Foamy macrophages –repair process leading to gliosis
Gliosis is CNS equivalent of fibrosis

Question 14

How would an aneurysm form in the cerebral arteries

Answer 14

the cerebral arteries have thin walls.

Weakening of wall + hypertension causes aneurysm to form

Question 15

2 common sites of ruptured vessels causing haemorrhagic stroke:

Answer 15

Basal ganglia – microaneurysms form in hypertensive patients

Circle of Willis – Berry aneurysm forms in hypertensive patient

Question 16

What can cause generalised interrupted blood supply or hypoxia

Answer 16

Low O2 in blood (hypoxia with intact circulation of blood)
Inadequate supply of blood (flow of blood not occurring) – blood may be oxygenated or not
Rarely: Inability to use O2 – eg cyanide poisoning

Question 17

Define Watershed infarcts

Answer 17

Pure hypotension with oxygenated blood

Question 18

3 main causes of localised interrupted blood supply

Answer 18

Atheroma + thrombosis of artery causing ischaemia
Thromboembolism (for example, from left atrium) causing ischaemia
Ruptured aneurysm of a cerebral vessel causing haemorrhage

Question 19

3 examples of brain injury caused by generalised interrupted blood supply

Answer 19

a. Hypotension  watershed infarction
b. Cardiac arrest  cortical infarction
c. Complex case  complex pattern