Stroke Flashcards
1
Q
Definition of stroke
A
Neurological deficit (loss of function) of sudden onset, lasting more than 24 hours, of vascular origin
2
Q
What time defines a TIA?
A
< 24 hours
3
Q
What does TIA stand for?
A
Transient ischaemic attack
4
Q
Two types of causes of stroke
A
- Ischaemic stroke
2. Haemorrhagic stroke
5
Q
What is the penumbra?
A
Area of tissue in the brain that can get some oxygen from other places and so is “asleep” - not dead
6
Q
Causes of haemorrhage in stroke
A
Congenital weakness
HTN
Aneurysm
7
Q
What do the symptoms of stroke correlate to?
A
Part of the brain affected
8
Q
Main anatomical vessels of the brain
A
Anterior circulation
Posterior circulation
Circle of willis
9
Q
What supplies the anterior part of the brain?
A
Two carotid arteries
10
Q
What joins together to form the circle of willis?
A
Anterior and posterior circulations
11
Q
Where is a clot most likely to go in the circle of willis?
A
Middle cerebral artery (MCA)
12
Q
What does the carotid system supply?
A
Most of the hemispheres
Cortical deep white matter
13
Q
What does the vertebra-basilar system supply?
A
Brainstem
Cerebellum
Occipital
14
Q
What is found anterior to the central sulcus?
A
Motor cortex
15
Q
What is found posterior to the central sulcus?
A
Sensory cortex
16
Q
Function of motor cortex
A
Movement
17
Q
Function of sensory cortex
A
Pain, heat and other sensations
18
Q
Function of parietal lobe
A
Comprehension of language
19
Q
Function of temporal lobe
A
Hearing
Intellectual and emotional functions
20
Q
Function of occipital lobe
A
Primary visual area
21
Q
Function of wernickes area
A
Speech comprehension
22
Q
Function of cerebellum
A
Coordination
23
Q
Function of brainstem
A
Breathing Swallowing Heartbeat Wakefullness centre Involuntary functions
24
Q
Function of Brocas area
A
Speech
25
Function of frontal lobe
Smell
Judgement
Foresight
Voluntary movement
26
Definition of TIA
Warning stroke or mini stroke, with stroke like symptoms persisting less than 24 hours, that clears without residual ability
27
How many patients who have a TIA will have an acute stroke at some point?
1/3rd
28
Causes of stroke
Blockage of vessel with thrombus or clot
Disease of vessel wall e.g. atheroscleroma
Disturbance of normal properties of the blood e.g. leukaemia
Rupture of the vessel wall (haemorrhage)
29
What % of strokes are due to infarction?
85%
30
What % of strokes are due to haemorrhage?
15%
31
Causes of ischaemic stroke
```
Large artery atherosclerosis (e.g. carotid)
Cardioembolic (e.g. AF)
Small artery occlusion (lacunar)
Undetermined/cryptogenic
Rare causes
- arterial dissection
- venous sinus thrombosis
```
32
Causes of haemorrhagic stroke
Primary ICH
Secondary haemorrhage
- SAH
- AV malformation
33
How does a haemorrhagic stroke affect the brain?
Blood causes pressure effects and squashes the surrounding brain tissue
34
Where do most carotid stenosis occur?
Bifurcation
35
Commonest cause of cardioembolic stroke
AF
36
What does AF stand for?
Atrial fibrillation
37
What does a carotid dissection look like on angiogram?
Rat tail appearance
38
Risk factors for stroke
```
High BP
AF
Age
Race
FH
```
39
Which type of stroke is more prevalent in high income countries?
Ischaemic
40
Risk factors for haemorrhage after stroke
```
Infarct size
Vessel occlusion
DM
BP
Age
Stroke severity
Tissue changes
Antiplatelets
```
41
What is the time frame for giving someone thrombolysis when admitted with stroke?
4.5 hours
42
What should not be used for treatment of patients in the acute phase for stroke?
Streptokinase
43
Examples of neurological deficits seen in stroke
Facial weakness
Limb weakness
Speech disturbances (dysphasia or dysarthria)
Hemianopia
44
Contraindications to thrombolysis
Minor neurological deficit or symptoms rapidly improving before the start of infusion
Symptoms of ischaemic attack began more than 4 hours prior to referral, or when time of symptom onset is unknown
Severe stroke
Seizure at onset of stroke
Symptoms suggestive of SAH, even if CT scan is normal
On warfarin or administration of heparin within the previous 48 hours and a thromboplastin time exceeding upper limit
Patients with history of prior stroke AND concomitant stroke
Prior stroke within last 3 months
Platelet count below 100,000/mm3
Systolic BP >185mmHg or diastolic >100mmHg or aggressive meds needed to reduce BP to these limits
BG < 3 or > 20
Known haemorrhagic diathesis , recent severe or dangerous bleeding, known ICH
age > 16 and < 80
45
Who needs a hemicraniectomy in stroke?
Patients up to age 60, who suffer acute MCA territory ischaemic stroke complicated by massive cerebral oedema
46
When should a hemicraniectomy be given?
Within 48 hours of stroke onset
47
Why do stroke units improve morbidity and mortality?
Mobilise early
Swallowing, positioning focus
Early therapy
Concentrating of expertise
48
What % of stroke patients get swallowing problems?
50%
49
What is the Neumonic used by the public to remember stroke symptom recognition?
FAST
50
Secondary prevention of stroke
Clopidogrel or aspirin 75mg plus dipyridamole MR 200mg bd
Statin
BP drugs (even if in normal range)
Carotid endarterectomy
51
Presentation of stroke
```
Dead numbness
Loss of vision
Loss of speech (fluid or comprehensive)
Loss of power
Loss of sensation
Loss of coordination
```
52
What may the neurological exam of a stroke show?
```
Clumsy or weak limb
Loss of sensation
Dysarthria/dysphagia
Neglect/visuospatial problems
Loss of vision in one eye
Hemianopia
Gaze palsy
Ataxia/vertigo/incoordination/nystagmus
```
53
If there is a left optic nerve compression, what visual field defect would be present?
Unilateral field loss
54
If there is chiasmal compression from a pituitary tumour, what visual field defect would be present?
Bitemporal hemianopia
55
If there is a left cerebrovascular event, what visual field defect will be present?
Homonymous hemianopia
56
What parts of the brain can a stroke be localised to?
Left or right
Carotid territory or vertebrobasilar territory
Cerebral hemispheres or brainstem
Cortex or deep white matter
57
Subtypes of stroke
TACS
PACS
LACS
POCS
58
What does TACS stand for?
Total anterior circulation stroke
59
What does PACS stand for?
Partial anterior circulation stroke
60
What does LACs stand for?
Lacunar stroke
61
What does POCS stand for?
Posterior circulation stroke
62
What % of strokes are TACS?
20%
63
Presentation of TACS
Weakness
Sensory deficit
Homonymous hemianopia
Higher cerebral dysfunction (e.g. dysphagia, dyspraxia)
64
What are TACS usually due to?
Occlusion of
- proximal MCA or
- ICA
65
What % of strokes are PACS?
35%
66
Presentation of PACS
2/3 of TACS criteria OR
| Restricted motor/sensory deficit e.g. one limb, face and hand or cerebral dysfunction alone
67
What is usually affected in PACS?
More restricted cortical infarcts - occlusion of branches of MCA
68
Presentation of LACS
Since motor fibres travel together and sensory fibres travel together can be either PURE SENSORY or PURE MOTOR
PURE MOTOR is commonest; complete or incomplete weakness of one side, involving 2 or 3 body areas (face/arm/leg)
Ataxic hemiparesis
69
What is ataxic hemiparesis?
Hemiparesis and ipsilateral cerebellar ataxia
70
What causes ataxic hemiparesis in LACS?
Small infarcts in basal ganglia or pons
| Intrinsic disease of single basal perforating artery
71
What % of strokes are POCS?
25%
72
What areas can POCS affect?
Brainstem
Cerebellum
Occipital lobe
73
Presentation of POCS
```
Variable, frequently complex
Bilateral motor / sensory deficit
Disordered conjugate eye movement
Isolated homonymous hemianopia
Ipsilateral CN palsy with contralateral sensory / motor deficit
Coma
Disordered breathing
Tinnitus
Vertigo
Horner's
```
74
Which type of stroke has the highest mortality?
TACS
75
Which type of stroke has the highest recurrence rate at 1 year?
POCS
76
Investigations for stroke
```
FBC
Lipids
ECG
CT
MRI
Carotid doppler
ECHO
```
77
What should patients with AF post stroke be started on?
Anticoagulation with warfarin or another anticoagulant
78
What to do with haemorrhagic stroke if on warfarin?
Stop warfarin
Give IV Vit K
Prothrombin complex concentrate
79
Management of a patient with AF who has a stroke/TIA
Warfarin or a direct thrombin or factor Xa inhibitor
80
What should be started in a patient with a TIA in the absence of AF?
Clopidogrel
81
When should a patient with acute stroke (not haemorrhagic) have their anticoagulation started? Why?
2 weeks after the event
| Due to the risk of hae morrhagic transformation
82
What anti-platelet medication should a patient be put on following a stroke?
Aspirin 300mg daily for 2 weeks THEN
| Clopidogrel 75mg daily lifelong
83
What does the ABCD2 score look at?
Predicts stroke risk following TIA
