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Cardiovascular System > Stroke > Flashcards

Flashcards in Stroke Deck (58)
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1
Q

What is it a stroke?

A

A neurological deficit ( loss of function) of sudden onset and lasting more than 24 hours. It is of vascular origin.

2
Q

Describe the circulation in the head

A

Carotid aa. supplies anterior circulation

Vertebro-basilar supplies posterior circulation

3
Q

How can haemorrhage cause a stroke?

A

Blood builds up in the white matter and compresses brain tissue

4
Q

If a stroke is small but affects deep white fibres what will the result be?

A

Can cause major deficit as the fibres are packed close together

5
Q

What are the causes of a stroke?

A
Occlusion due to thrombus or clot 
Disease of vessel wall 
Disturbance of normal blood due to infection (increases WBC)
Rupture of vessel wall - haemorrhage 
Carotid stenosis 
Cardioembolic
6
Q

What can a carotid stenosis cause a stoke?

A

Bifircation of a vessel is a common place for atheroma to develop due to turbulent blood flow

If it partially occludes vessel, perfusion can still occur and leads to formation of a thrombus which can detach and occlude another vessel (embolism)

7
Q

How does a cardioembolic stroke occur?

A

AF dislodges clots in LA and the thrombus travels to brain and occludes vessel

8
Q

What are the symptoms of a stroke?

A
Loss of:
Power
Sensation 
Speech (dysphasia)
Vision 
Coordination
9
Q

What are the two types of strokes?

A

haemorrhagic or ischaemic

10
Q

What investigations should be carried out for stroke?

A
Blood: FBC, lipids
ECG
CT - identify haemorrhage (shows blood)
MRI - shows area of infarct  
Carotid doppler 
Echo
11
Q

What are the treatment options?

A

Thrombolysis
Hemicraniotomy
Carotid endarectomy for carotid stenosis

12
Q

What is the use of hemicraniotomy

A

For <60yrs who suffer an acute MCA territory ischaemic stroke complicated by massive cerebral oedema

Surgical decompression by hemi offered within 48hr

13
Q

How does a stroke occur?

A

Damage to part of the brain due to blockage of vessels by thrombus or embolus, or haemorrhage due rupture of vessels

Tissue then does not receive adequate O2 nutrition -> necrosis

14
Q

What is a transient ischaemic attack?

A

A neurological deficit of sudden onset and vascular origin that last less than 24hours

15
Q

What is aphasia/dysphasia?

A

Language disorder marked by deficiency in the generation of speech

16
Q

What can be found in the history of a stroke?

A
Time of onset 
Witnesses
Headache
Vomiting
Neck stiffness
Photophobia (suggest haemorrhage)
Loss of consciousness 
Fit 
Incontinence
17
Q

What are the findings on clinical examination?

A
Motor (clumsy or weak limbs)
Sensory (loss of feeling)
Speech (dysarthria/dysphasia)
Neglect/visuospatial problems
Vision: loss in one eye, or hemianopia
Gaze palsy

Ataxia
Vertigo
Incoordination
Nystagmus

18
Q

What is Nystagmus?

A

A condition in which the eyes make repetitive and uncontrolled movements - sign of stroke

19
Q

Dysarthia vs aphasia

A

Dysarthia - weakened muchness around mouth

Dysphasia - problem finding words.

20
Q

What are three circulations in the brain?

A

Anterior circulation
Posterior circulation
Circle of Willis

21
Q

What is the frontal lobe responsible for?

A

Judgement, foresight and voluntary movement

22
Q

What is the parietal lobe responsible for?

A

Comprehension of language

23
Q

What is the occipital lobe responsible for?

A

Vision

24
Q

What is the function of the brain stem?

A

Swallowing, breathing, heartbeat

25
Q

What does the carotid artery supply?

A

Most of the hemispheres and critical deep white matter

26
Q

What does the vertebra basilar system supply?

A

the brain stem, cerebellum and occipital lobes

27
Q

What is the function of the cerebellum?

A

Coordination

28
Q

What is the function of the motor cortex?

A

Movement

29
Q

What is the function of the Broca’s area?

A

Speech

30
Q

What is the function of the temporal lobe?

A

Intellectual and emotional functions

31
Q

What is a lacunar stroke?

A

An ischemic stroke when the small arteries deep within the brain becomes blocked

32
Q

How can a carotid dissection cause a stroke?

A

Separation of the layers on the vessel wall, allowing blood to enter and compress truth artery channels resulting in a total artery occlusion and form a thrombus

33
Q

What can you tell from the symptoms about the stroke?

A
Which side of brain is affected 
If in the brainstem 
If cortex is involved 
If lesion is in the deep white matter 
What blood vessel in involved
34
Q

Where has the occlusion occurred in a cortical stroke?

A

Cortex

35
Q

Why is it important to localise the stroke?

A

Confirms stroke diagnosis
All better selection of imaging
Gives an indication of cause
Gives indication of prognosis

36
Q

How can vision suggests the location of lesion?

A

Type of visual eye defect gives indication

37
Q

What are the 4 subtypes of strokes?

A

Total anterior circulation stroke
Partial anterior circulation stroke
Lacunar stroke
Posterior circulation stroke

38
Q

What are the three visual field defects?

A
Unilateral field loss 
Bitemporal hemianopia (tunnel vision)
Homonymous haemianopia (can't see on one side)
39
Q

Describe effect of a total anterior circulation stroke

A

Weakness, sensory deficit
Homonymous hemianopia
Higher cerebral dysfunction (dysphasia, dyspraxia)

Usually due to occlusion of proximal middle cerebral artery or internal carotid artery

40
Q

Describe the effect of a partial anterior circulation stroke

A

2/3 of TACS criteria or restricted motor/sensory deficit

Occlusion of branches of middle cerebral artery

41
Q

What are the different types of lacunar strokes?

A

Pure motor
Pure sensory
Sensorimotor
Ataxic hemiparesis - in basal ganglia or pons

Often silent - undiagnosed

42
Q

What is the presentation of a posterior circulation stroke?

A
Affect brainstem, cerebellar or occipital lobes, may include:
Bilateral sensory/motor deficit 
Homonymous hemianopia 
Cranial nerve palsy 
Coma 
Disordered breathing 
Tinnitus 
Vertigo
Horner's
43
Q

What is important to remember about the symptoms of a stroke?

A

Symptoms come on rapidly

Symptoms depend on which part of the brain is affected

44
Q

What are modifiable risk factors of stroke?

A

Atrial fibrillation

High blood pressure

45
Q

What are non-modifiable risk factors for stroke?

A

Age
Race
FH

46
Q

CT vs MRI

A

CT: quick and shows blood
MRI: 30 mins and shows ischaemia better

47
Q

What is the purpose of carrying out a carotid doppler?

A

Looks at vessels

48
Q

Why can an echo be useful?

A

Looking for clots in the heart

49
Q

Why can an ECG be useful?

A

Detecting irregularities in heart rhythm — such as atrial fibrillation — that can lead to the forming of blood clots that can later get flow to the brain

50
Q

What is the importance of stroke units?

A
Better prognosis of patient:
Mobilise ASAP
Concentrate of simple tasks i.e. swallowing 
Early therapy 
Expertise
51
Q

What is the aim of thrombolysis?

A

To restore perfusion before cell death occurs

52
Q

What are the risks of haemorrhage occurring after thrombolysis?

A
Depends on:
Infarct size 
Vessel occlusion 
Diabetes 
BP
Age Stroke severity 
Tissue changes 
If already on anti platelets
53
Q

What is an invasive method to enable reperfusion?

A

Clot retrieval

54
Q

What are the contradictions to thrombolysis?

A

Age - licenced for <80yrs

55
Q

What is a hemicraniectomy?

A

The surgical removal of half of the cranium to enable brain surgery

56
Q

What fraction of people who have a TIA will go on to have an acute stroke?

A

1/3

57
Q

How can people who have TIAs reduce risk of recurrent stroke?

A

Early treatment for prevention

58
Q

What drugs are given for secondary prevention of a stroke?

A

Aspirin 75mg
or
Clopidogrel 75mg

Statin
BP drugs, even if BP in normal range