Stroke

Question 1

What is a stroke?

Answer 1

development of a focal or global neurological deficit related to a vascular event

Question 2

What are the three types of strokes?

Answer 2

infarction, haemorrhagic and subarachnoid haemorrhage (non traumatic)

Question 3

What are the risk factors for cerebral infarction?

Answer 3

age, hypertension, cardiac disease, hyperlipidaemia, diabetes mellitus, hyper coagulable state, smoking, obesity

Question 4

What is a cerebral infarction?

Answer 4

necrosis of cerebral tissue in a particular vascular distribution due to vessel occlusion or severe hypoperfusion

Question 5

Can a venous occlusion cause a cerebral infarction?

Answer 5

yes - if the venous outflow is obstructed then arterial pressure won’t be enough to get blood to the brain

Question 6

What are the 3 mechanisms of cerebral infarction?

Answer 6

inadequate supply of blood due to pump failure, inadequate supply of blood due to vessel narrowing, vessel occlusion by embolus

Question 7

What are the different mechanisms of vessel narrowing?

Answer 7

atherosclerosis, thrombosis, hypertensive vessel thickening, diabetes, amyloid angiopathy

Question 8

What is the most common cause of cerebral infarction?

Answer 8

embolic large artery occlusion

Question 9

If the cerebral infarct is caused by a small vessel occlusion is it more likely to be an embolus or a thrombus?

Answer 9

thrombus

Question 10

If the cerebral infarct is caused by venous occlusion is it more likely to be an embolus or a thrombus?

Answer 10

it is always thrombotic - never an embolism

Question 11

Where does an embolus causing a cerebral infarction come from?

Answer 11

cardiac valve vegetations, atherosclerosis in the vertebral artery, basilar artery, termination of ICA and proximal MCA, atrial fibrillation, left ventricular aneurysm

Question 12

What is the significance of a patent interventricular septum for a cerebral infarction?

Answer 12

an embolus can get from the right side of the heart to the brain

Question 13

What is the treatment for carotid atherosclerosis?

Answer 13

carotid endarterectomy - stripping out of the intima and part of the media

Question 14

What is visible macroscopically 36 hours after a cerebral infarction?

Answer 14

swelling, herniation, loss of demarcation between grey and white matter

Question 15

Why does the brain swell about 36 hours after a cerebral infarction?

Answer 15

cytotoxic oedema

Question 16

What is a potential consequence of the swelling due to cerebral infarction?

Answer 16

patient can die from raised ICP causing transtentorial herniation and brainstem haemorrhages

Question 17

What type of necrosis occurs in the brain?

Answer 17

liquefactive

Question 18

What is visible macroscopically days to weeks after a cerebral infarction?

Answer 18

tissue break down - sharp demarcation between area of infarct and healthy brain

Question 19

What is visible macroscopically months to years after a cerebral infarction?

Answer 19

cystic space

Question 20

What is a possible cause of several small haemorrhagic infarcts throughout the brain?

Answer 20

an aneurysm in the left ventricle has caused several thrombo-emboli to be sent up to the brain and when the emboli are lysed and the area is reperfused a secondary haemorrhagic infarction occurs

Question 21

What is the risk of treatment with tPA for a cerebral infarction?

Answer 21

reperfusion injury - secondary haemorrhagic infarction

Question 22

What is the result of hyaline arteriolosclerosis in the brain?

Answer 22

can either get rupture and haemorrhage due to a weak vessel wall (more likely) or can cause occlusion and result in an infarction

Question 23

What is a lacunar infarction?

Answer 23

small infarcts in the brain due to small vessel disease (hyaline arteriolosclerosis) - often not clinically apparent unless in an area such as the internal capsule or the pons

Question 24

Why do people die after a cerebral infarction?

Answer 24

either due to direct effects such as involvement of vital centres or cerebral swelling or more commonly due to indirect effects such as pneumonia or pulmonary thromboembolism from immobilisation or cardiovascular disease due to the risk factors which lead to the cerebral infarction

Question 25

What are the causes of intracerebral haemorrhage?

Answer 25

hypertensive small vessel disease (hyaline arteriolosclerosis), amyloid angiopathy, blood disorders, tumour, vasculitis, vascular malformation (arteriovenous malformation), drugs

Question 26

What particular sites in the brain are likely to be affected by an intracerebral haemorrhage due to hyaline arteriolosclerosis?

Answer 26

basal ganglia (putamen), thalamus, lobar white matter, cerebellum, pons

Question 27

What particular area in the brain is likely to be affected by an intracerebral haemorrhage due to amyloid angiopathy?

Answer 27

superficial areas

Question 28

If there are multifocal haemorrhages what is a likely cause?

Answer 28

coagulopathy

Question 29

What are the causes of a non traumatic subarachnoid haemorrhage?

Answer 29

rupture of a congenital berry aneurysm, rupture of other types of aneurysm (atherosclerotic or infective), extension of intracerebral haemorrhage

Question 30

What are the risk factors for developing a berry aneurysm?

Answer 30

younger age, female, polycystic kidney disease, coarctation of aorta (congenital narrowing), type III collagen deficiency, hypertension, smoking, alcohol

Question 31

What are the particular sites favoured for berry aneurysms?

Answer 31

trifurcation of the ICA, anterior communicating artery and first bifurcation of the MCA

Question 32

What are the complications of an aneurysm rupture?

Answer 32

subarachnoid haemorrhage, intraparenchymal haemorrhage, cerebral oedema and raised ICP, vasospasm and infarction, ventricular obstruction and hydrocephalus

Question 33

What is a watershed infarct and where do they occur?

Answer 33

an infarct due to low cardiac output - occurs at the border zone of vascular supply where there is poor collateral circulation