Pathology of Cerebrovascular Disease: Ischaemia and Hypoxia

Question 1

Which artery is the middle cerebral artery a continuation of?

Answer 1

Internal carotid artery

Question 2

Ischaemia?

Answer 2

Lack of blood flow

Question 3

Hypoxia?

Answer 3

Lack of oxygen

Question 4

What can ischaemia often lead to?

Answer 4

Hypoxia

Question 5

What causes a stroke?

Answer 5

Disruption to blood supply of brain. This leads to an interruption in oxygen and nutrient supply to brain causing brain tissue damage

Question 6

The interruption of supply of oxygen to the brain can be caused by changes in which things?

Answer 6

1. Changes in vessel wall
2. Changes in blood flow
3. Changes in blood constituents

Question 7

What could cause a change to the vessel wall and disrupt blood flow?

Answer 7

Atheroma
Vasculitis
Outside pressure e.g. spinal cord compression, strangulation

Question 8

What could cause a change to the blood constituents and disrupt blood flow?

Answer 8

Thrombosis of arteries
Bleeding due to anticoagulation
Reduced platelets and clotting factors

Question 9

In practice, there are three main causes of localised interrupted blood supply. List them.

Answer 9

1. Atheroma and thrombosis of an artery
2. Thromboembolism
3. Ruptured aneurysm

Question 10

What would atheroma and thrombosis do to the artery?

Answer 10

Narrows it

Question 11

What are the components of thrombosis?

Answer 11

Platelets and fibrin

Question 12

If there was atheroma and thrombosis of an artery, what could this cause?

Answer 12

Ischaemia

Question 13

If there was internal carotid artery thrombosis, in which area would there be ischaemia?

Answer 13

Middle cerebral artery region

->middle cerebral artery is a branch of the internal carotid arteries

Question 14

When are ischaemic symptoms classified as transient?

Answer 14

If they last less than 24hrs

Question 15

When are ischaemic symptoms classified as longstanding?

Answer 15

If they last more than 24hrs

Question 16

If there is transient ischaemia, what happens to the brain tissue?

Answer 16

Still viable as this process is reversible

Question 17

If there is longstanding ischaemia, what happens to the brain tissue?

Answer 17

Infarct as death to brain tissue due to irreversible ischaemia

Question 18

Anoxia?

Answer 18

Total loss of oxygen

Question 19

What can hypoxia/anoxia of the brain lead to?

Answer 19

Infarction

Question 20

Is infarction reversible?

Answer 20

No as neuronal damage is permanent and neurons do not regenerate

Question 21

Which cells in the brain have a role in inflammation and act as the macrophages in the brain?

Answer 21

Microglial cells

Question 22

What is the name given to the CNS version of fibrosis?

Answer 22

Gliosis

Question 23

Which heart related condition is it more common to get thrombosis?

Answer 23

Atrial fibrillation

Question 24

If there is a thrombosis in the left atrial appendage and it breaks off, where will it embolise to?

Answer 24

Aorta and potentially carotid arteries

Question 25

What does thromboembolism cause?

Answer 25

Ischaemia

Question 26

Which type of stroke would thromboembolism or atheroma/thrombosis lead to?

Answer 26

Ischaemic stroke

Question 27

In which condition are the thin walled arteries of the brain more likely to rupture?

Answer 27

In those with hypertension ->this is why hypertension is the biggest risk factor for strokes!!!!

Question 28

What would a ruptured vessel in the brain lead to?

Answer 28

Haemorrhage and ischaemia ->as reduced blood flow to part after the rupture as all blood leaking through the rupture

Question 29

What are the two common sites of ruptured vessels causing haemorrhagic stroke?

Answer 29

Basal ganglia Circle of Willis

Question 30

Which type of aneurysm forms in hypertensive patients in the basal ganglia?

Answer 30

Microaneurysms

Question 31

Which type of aneurysm forms in hypertensive patients in the Circle of Willis?

Answer 31

Berry aneurysm

Question 32

A berry aneurysm in the Circle of Willis can give rise to what?

Answer 32

Subarachnoid haemorrhage

Question 33

When may there be a generalised interrupted blood supply, potentially causing hypoxia?

Answer 33

-Low oxygen in blood -Inadequate supply of blood

Question 34

In which situations would there be low oxygen levels in blood?

Answer 34

Carbon monoxide poisoning, near drowning, respiratory arrest

Question 35

In which situations would there be an inadequate supply of blood?

Answer 35

Cardiac arrest Hypotension Brain swelling

Question 36

What name is given to zones of infarction at interface of artery perfusion territories?

Answer 36

Watershed infarcts

Question 37

What does complete loss of perfusion and oxygen* lead to? *e.g. someone has had a cardiac arrest and all blood flow stops

Answer 37

Cortical necrosis

Question 38

Which type of infarction could someone get if they had hypotension?

Answer 38

Watershed infarction