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MD1 Neuroscience > Stroke > Flashcards

Flashcards in Stroke Deck (57):
1

Define stroke

Clinical term
Development of focal/global neurological deficit related to vascular event

2

Can transient clinical events occur due to vascular events?

Yes

3

Can vascular events go undetected clinically?

Yes

4

What are the pathological processes involved in stroke?

Infarction
Haemorrhage
Subarachnoid haemorrhage

5

What percentage of strokes are caused by infarction?

75%

6

What is an infarction?

Death of tissue due to inadequate blood supply

7

What percentage of strokes are caused by haemorrhage?

20%

8

What is a haemorrhage?

Tissue injury due to escape of blood from vessels

9

What percentage of strokes are caused by subarachnoid haemorrhage?

5%

10

What is a subarachnoid haemorrhage?

Escape of blood primarily into subarachnoid space

11

What is the third leading cause of death?

Stroke

12

What are the risk factors for cerebral infarction?

Ageing
Hypertension
Cardiac disease; eg: atrial fibrillation
Hyperlipidaemia
Diabetes
Hypercoagulable states
Smoking
Obesity

13

What happens in a cerebral infarct?

Necrosis of cerebral tissue in particular vascular distribution
Due to vessel occlusion/severe hypoperfusion

14

What is cerebral infarction usually related to?

Arterial obstruction

15

Where can the primary problem causing a cerebral infarct be?

Arterioles
Veins
Heart

16

What are the possible mechanisms of infarction?

Inadequate supply of blood due to pump failure
Inadequate supply of blood due to narrowed vessel lumen
- Atherosclerosis
- Thrombosis
- Hypertensive vessel thickening
- Diabetes
- Amyloid angiopathy
Vessel occlusion by embolus

17

Why is haemorrhage more likely than infarction if you have an amyloid angiopathy?

Wall thickens > weakens
Lumen narrowed

18

What can cause a large artery occlusion?

Thrombosis
Embolus

19

What can cause a small vessel occlusion?

Thrombosis
Embolus

20

What can cause a venous occlusion?

Thrombosis

21

How can infective endocarditis cause a cerebral infarction?

Mycotic embolus blocks vessel

22

What percentage of people have a probe-patent interatrial septum?

30%

23

What is a probe-patent interatrial septum?

Flap that can be open

24

How can a probe-patent interatrial septum contribute to a cerebral infarct?

If right heart pressure increased > embolus crosses into left atrium from right > travels up into cerebral vessel > occlusion

25

What are the common sites of atherosclerosis in the circle of Willis?

Anterior circulation at bifurcation
Vertebral artery
Basilar artery
Internal carotid artery

26

How do thrombi form in atherosclerotic vessels?

Narrowing of vessel lumen
Irregularities in intima
Lend themselves to thrombus formation

27

Where is an embolus more common?

In aortic and internal carotid branches than vertebro-basilar system

28

What does the brain look like within one hour of a cerebral infarct?

Relatively normal

29

How does cerebral oedema form?

Cells swell because of cytotoxic oedema
Vasogenic oedema in vascularised edges

30

What does cerebral oedema cause?

Raised intracranial pressure

31

What happens to the gyri and sulci around the swelling tissue?

Gyri expand
Sulci are obliterated

32

What does the brain look like macroscopically in the days/weeks after a cerebral infarct?

Clear interface between dead and normal tissue
Liquefactive necrosis

33

What does liquefactive necrosis look like microscopically?

Massive influx of macrophages
More and more cavitation
Some surviving blood vessels with a little new growth
Neurons don't regenerate

34

What does the brain look like in the months/years after a cerebral infarct?

Infarcted area replaced by cavity

35

What are most cerebral infarcts caused by: thrombus or embolus?

Embolus

36

How does a haemorrhagic infarct happen?

Embolus lodges > tissue necrosis, damage to blood vessels > embolus removed, naturally/iatrogenically > reperfusion into necrotic area > weakened blood vessels rupture > haemorrhage over necrosis

37

Why must blood be restored before complete necrosis?

Avoid haemorrhagic infarction

38

What is hyaline arteriolosclerosis?

Small vessel disease associated with hypertension

39

What causes lacunar infarcts?

Hyaline arteriolosclerosis

40

In which areas do lacunar infarcts usually occur?

Basal ganglia
Internal capsule

41

Why do people with cerebral infarction die?

Most people
- Pneumonia
- Cardiovascular disease
- Pulmonary thromboembolism
Involvement of vital centres
Cerebral swelling

42

What are the effects of raised intracranial pressure?

Transtentorial herniation
Brainstem haemorrhages

43

What are the two most common causes of intracerebral haemorrhage?

Hypertensive small vessel disease
Congophilic/amyloid angiopathy

44

Which demographic is amyloid angiopathy most common in?

Older people

45

What are the causes of intracerebral haemorrhage?

Hypertensive small vessel disease
Amyloid angiopathy
Blood disorders
Tumour
Vasculitis
Vascular malformation
Drugs

46

What is a hypertensive haemorrhage?

Presence of small vessel disease like hyaline arteriolosclerosis

47

In which sites is hypertensive haemorrhage likely to occur?

Basal ganglia
Thalamus
Lobar white matter
Cerebellum
Pons

48

What is amyloid angiopathy?

Deposition of beta amyloid in walls of superficial supratentorial blood vessels

49

What type of haemorrhage is amyloid angiopathy associated with?

Superficial haemorrhages
Often multiple and of varying age

50

Which neurodegenerative disease is amyloid angiopathy associated with?

Alzheimer's disease

51

What are the non-traumatic causes of subarachnoid haemorrhage?

Rupture of saccular/berry aneurysm in circle of Willis and its branches
Rupture of other aneurysms
- Mycotic
- Atherosclerotic
Extension of intracerebral haemorrhage

52

What does it mean by a congenital berry aneurysm?

Aneurysm develops at sites of congenital weakness
Aneurysm develops with ageing

53

What are the risk factors for developing a saccular aneurysm?

Age
Polycystic kidney disease
Coarctation of aorta
Type III collagen deficiency
Hypertension
Smoking/alcohol

54

Where do 90% of aneurysms form?

In anterior circulation of circle of Willis

55

Where are sites of congenital weakness in the circle of Willis?

Arterial bifucations

56

What are the most common sites of berry aneurysm formation?

Bi/trifurcation of middle cerebral artery
Junction of internal carotid artery and posterior communicating artery
Anterior communicating artery

57

What are the complications of an aneurysm rupture?

Subarachnoid haemorrhage
Cerebral oedema and raised intracranial pressure
Vasospasm and infarction
Ventricular obstruction > hydrocephalus

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