Stroke

Question 1

What is stroke?

Answer 1

Development of focal or global neurologic deficit related to a vascular event

Question 2

Are strokes always visible?

Answer 2

Yes

But ‘silent’ vascular events may occur

Question 3

Describe the pathologic processes involved in stroke, and the percentage of patients in which they occur?

Answer 3

Infarction (75%)

Haemorrhage (20%)

Subarachnoid haemorrhage (5%)

Question 4

What are the risk factors for cerebral infarction?

Answer 4

Ageing

Hypertension

Cardiac disease

Hyperlipidaemia

Diabetes Mellitus

Hypercoagulable states

Smoking

Obesity

Question 5

What is cerebral infarction?

Answer 5

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

Question 6

What is the cause of cerebral infarction?

Answer 6

Usually related to arterial obstruction

Can also be arterioles, veins, heart

Question 7

Describe the mechanisms of infarction?

Answer 7

Inadequate supply of blood due to pump failure

Inadequate supply of blood due to narrowed vessel lumen (atheroscelrosis, thrombosis, hypertensive vessel thickening, diabetes, amyloid angiopathy)

Vessel occlusion by embolus

Question 8

Describe the causes of occlusion in vessels that cause cerebral infacrtion?

Answer 8

Large artery occlusion: thrombotic, may be embolic

Small vessel occlusion: thrombotic, may be embolic

Venous occlusion: thrombotic

Question 9

Describe this pathology, and how it relates to stroke?

Answer 9

Valve vegetations

Due to non-bacterial thrombotic endocarditis

Vegetations can enter the systemic circulation

Question 10

Describe this pathology, and how it relates to stroke?

Answer 10

Probe-patent interatrial septum

Potential for thrombus that form in venous system to pass from RA to LA, and then enter the brain

Question 11

What is the most common site for thrombi to develop?

Answer 11

Venous system

Question 12

Describe this pathology, and how it relates to stroke?

Answer 12

Atherosclerosis in Circle of Willis

Common sites: vertebral arteries, basilar artery, internal carotid termination artery, proximal middle cerebral artery

Question 13

Describe this pathology, and how it relates to stroke?

Answer 13

Thrombotic vessel occlusion in atherosclerosis

Question 14

Describe this pathology, and how it relates to stroke?

Answer 14

LEFT: old carotid endarterectomy

RIGHT: recent carotid endarterectomy

Procedure is performed to prevent ulcerated or stenotic atherosclerosis from causing cerebral infarction

Question 15

Describe this pathology, and how it relates to stroke?

Answer 15

Swelling 36 hours after cerebral infarct

Due to cell membrane break down, accumulation of fluid and adjacent vasogenic oedema

Also herniation here

Question 16

Describe how a brain looks immediately after cerebral infarction?

Answer 16

Initially, appears normal

Then starts to swell

Lose demarcation between grey and white matter

Herniation may occur

Question 17

Describe this pathology, and how it relates to stroke?

Answer 17

Viable neurons centrally, surrounded by axonic-ischaemic neurons

Initally cells swell up, then neurons die, nucleus becomes pyknotic, and eventually disappears

Supporting glial cells have not died

Question 18

Describe this pathology, and how it relates to stroke?

Answer 18

Infarct that is days/weeks old

Swelling has gone down

Tissue breaks down

Cerebral tissue necrotic - macrophages mving in to remove dead tissue

Question 19

What is the pathology?

Answer 19

Liquefactive necrosis

Question 20

Describe this pathology, and how it relates to stroke?

Answer 20

Infarct after months/years

Loss of cerebral tissue

Question 21

Describe this pathology, and how it relates to stroke?

Answer 21

BRAIN: Cerebral haemorrhagic infarcts

Due to embolism from cardiac ventricle thrombus (small fragments of thrombus flicked up to brain)

HEART: Wall thinned, aneurysm of ventricle (can lead to thrombus)

Question 22

What is haemorrhagic infarction charcteristic of?

Answer 22

Embolic events

Question 23

Describe this pathology?

Answer 23

Haemorrhagic transformation in recent infarct

Question 24

Describe this pathology, and how it relates to stroke?

Answer 24

Hyaline arterioloscelrosis

Most usually due to hypertension

Vessel balloons > enlargement of vascular lumen > can rupture> haemorrhage or thrombosis

Vascular disease can be at small vessel level such as this

Question 25

Describe this pathology, and how it relates to stroke?

Answer 25

Old lacunar infarct Small vessel occlusion \> small infarct May not be clinically important if in less important areas of brain May be devastating if in important areas of brain

Question 26

Why do people with cerebral infarction die?

Answer 26

Most commonly, die of complications due to them being incapacitated or having other risk factors: pneumonia, cardiovascular disease, pulmonary thromboembolism May also die due to cerebral swelling or involvement of vital centres

Question 27

Describe the possible complications of raised ICP?

Answer 27

Herniation Brainstem haemorrhages

Question 28

What are the causes of intracerebral haemorrhage?

Answer 28

Hypertensive small vessel disease Congophylic (amyloid) angiopathy Blood disorders Tumour Vasculitis Vascular malformation Drugs

Question 29

Which vessels does amyloid angiopathy affect?

Answer 29

Small vessels Much more likely to affect vessels at periphery of brain

Question 30

What is the major cause of hypertensive haemorrhage? Where does it usually occur?

Answer 30

Small vessel disease due to hyaline arteriolosclerosis Usually occurs in basal ganglia/thalamus, lobar white matter, cerebellum or pons

Question 31

Describe this pathology, and how it relates to stroke?

Answer 31

Intracerebral haemorrhage Due to hyaline arteriolosclerosis Also an old contralateral 'slit' haemorrhage

Question 32

What is cerebral amyloid angiopathy?

Answer 32

Deposition of ab amyloid in walls of superficial supratentorial blood vessles

Question 33

What disease states is cerebral amyloid angiopathy associated with?

Answer 33

Superficial haemorrhages Alzheimer's disease

Question 34

Describe this pathology?

Answer 34

Amyloid angiopathy Senile plaque left of centre Thickening of walls of small vessels

Question 35

Describe this pathology?

Answer 35

Multifocal synchronous haemorrhages Due to coagulopathy Must be a systemic problem, due to multifocal lesions

Question 36

Describe this pathology?

Answer 36

Rupture of congenital ateriovenous malformation Following attempted therapeutic embolisation

Question 37

List the non-traumatic causes of subarachnoid haemmorhage?

Answer 37

Rupture of saccular/Berry aneurysm Rupture of other types of aneurysm (mycotic, atherosclerotic) Extension of intracerebral haemorrhage

Question 38

Describe the risk factors for developing saccular aneurysm?

Answer 38

Gender - female Age - in younger, not elderly Polycystic kidney disease Coarctation of aorta Type III collagen deficiency Hypertension Smoking/alcohol

Question 39

Describe this pathology?

Answer 39

Ruptured basilar artery due to saccular aneurysm

Question 40

Where do saccular aneurysms usually occur?

Answer 40

Sites of congenital weakness at arterial bifurcations More often in anterior circulation than posterior Favoured sites: bi/trifurcation of MCA, junction of ICA and posterior communicating artery, anterior communicating artery

Question 41

Describe this pathology?

Answer 41

Ruptured anterior communicating artery aneurysm With inter and intraventricular haemorrhage

Question 42

Describe the complications of aneurysm rupture? How are they prevented?

Answer 42

Subarachnoid haemorrhage Cerebral oedema and raised ICP Vasospasm Infarction Hydrocephalus due to ventricular obstruction Prevented by clipping neck of aneurysm to prevent further bleeding