STROKE Flashcards
Define stroke
Stroke is defined as an acute neurological deficit lasting more than 24 hours with infarction
ISCHAEMIC vs HAEMORRHAGIC STROKE %
ischaemic - 80
haemorrhagic 20
What is ischaemic stroke caused by
- Reduction in cerebral blood flow due to arterial occlusion/ blockage or stenosis. Typically divided into lacunar , thrombotic and embolic
- Sites such as carotid, verebral and basilar arteries - mostly carotid
- Infarcted area dies causing permanent deficit
Aetiology of ischaemic stroke
- Atherothromboembolism
- Cardioembolism - AF, post MI, IE
- Vasculitis
- Fat emboli
- Hyperviscosity syndrome - blood becomes too thick
What is an embolic stroke usually caused by
- usually a blood clot but fat ,air or clumps of bacteria
- atrial fibrilation
What are thrombotic strokes usually caused by
- thrombosis from large vessels
Primary investigations for stroke
- 1st line- non contrast CT head - to allow exclusion of haemorrhage
- Diffusion weighted MRI- gs to confirm after CT
- ECG- asses for AF or MI
- Bloods; hba1c, lipids, clotting screen, FBC (RBC), ESR (vasculitis), cholesterol
- CTA
What are haemorrhagic strokes caused by
- ruptured bv
- berry aneurysm rupture
What can haemorrhgaic strokes further be divided into
- intracerebral - bleeding within brain parenchyma
- subarachnoid- bleeding between pia mater and arachnoid mater
Stroke in ACA
ACA- weakness of feet and legs with maybe sensory loss, incontinence, drowsiness, Truncal ataxia
Stroke in MCA
MCA (contralateral) - speech comprehension and understanding, hands and arms weakness, dysphasia, aphasia, Homonymous hemianopia,
Stroke in PCA
- PCA - visual problems,
- Propagnosia - inability to recognise faces,
- Visual agnosia - cannot interpret visual ino
What happens if vertebrobasilar artery is infarcted
- Quadriplegia - symptom of paralysis that affects all a person’s limbs and body from the neck down
- Dysarthria
- Vertigo
- N/V
- Drowsiness
Stroke in either hemisphere would exhibit ?
Hemiparesis
Hemisensory loss
Visual field defect
CONTRALATERAL
Lacunar infarct
Deep branches of MCA that feed the basal ganglia , damaged vessels form cysts due to hyaline arteriosclerosis
FEAUTURES of stroke in dominant hemisphere
- usually left
- Language dysfunction
- Expressive dysphasia
- Receptive dysphasia
- Dyslexia
- Dysgraphia
non dominant hemisphere stroke features
- Anosognosia
- Neglect of paralysed limb
- Denial of weakness
- Visuospatial dysfunction
- Geographical agnosia
- Dressing apraxia
- Constructional apraxia
Key diagnostic factors for stroke ?
- unilateral weakness or paralysis in the face, arm or leg
- dysphasia
- ataxia
- visual disturbance
posterior circulation symptoms
- Unsteadiness
- Visual disturbance
- Slurred speech
- Headache
- Vomiting
- Others e.g. memory loss, confusion
Risk factors
- older age
- family history of stroke
- history of ischaemic stroke or TIA
- hypertension
- Smoking
- Male
- diabetes
- Vasculitis
- Hyperlipidaemia
What do haemorrhagic strokes tend to show ..
increased intracranial pressure
What is ROSIER
Recognition of Stroke in the Emergency Room
DD for stroke
- Hypoglycaemia
- Hyponatraemia
- Hypercalcaemia
- Uraemia
- Hepatic encephalopathy
increase in intracranial pressure is likely to cause ..?
midline shift
Management of ischaemic stroke
- immediate aspirin 300mg until 2 weeks after symptoms
- thrombolysis with IV alteplase ( tissue plasminogen ) to restablish blood flow - 4.5 hours within symptom onset
- contraindcations of Thrombolysis