Stroke: Ischaemic Stroke Flashcards
Definition
Rapid onset of neurological deficit
- lasting for more than 24 hours
- poor blood flow to brain causes cell death
Epidemiology
Older people
Males
Risk factors
Hypertension: the single greatest risk factor
Age: the average age for a stroke is 68 to 75 years old
Smoking
Diabetes
Hypercholesterolaemia
Atrial fibrillation
Family history
Haematological disease: such as polycythaemia
Medication: such as hormone replacement therapy or the combined oral contraceptive pill
Aetiology
Small vessel occlusion by thrombosis
Athero-embolism e.g. carotid artery
Cardioembolism
- AF, post MI, valve disease, infective endocarditis
Hyper viscosity
Vasculitis
Fat emboli from a long bone fracture
Venous sinus thrombus
Pathophysiology
Reduction in cerebral blood flow due to arterial occlusion or stenosis. Typically divided into thrombotic, embolic and lacunar.
Blood vessel to/in brain occluded by a clot
Ischaemia + infarction follow
- Infarcted areas dies, resulting in focal neurological symptoms
- Infarcted area is surrounded by a swollen area (oedema) which can regain function with neurological recovery
ACA Signs
If ACA:
- Leg weakness (since ACA supplies the area of the brain which controls the legs)
- Contralateral Hemiplegia + sensory loss (lower limbs more than upper limbs)
- Urinary + faecal incontinence (due to loss of bladder and genital function)
- Akinetic Mutism (will not speak or move, no motivation to do so)
MCA Signs
Upper body is affected (face, arms, ect.)
Contralateral hemiplegia (upper limbs more than lower) + sensory loss
Homonymous hemianopia
- DOMINANT SIDE = APHASIA
Wernicke’s Aphasia (aka receptive aphasia) = cannot understand speech
Broca’s Aphasia (aka Expressive Aphasia) = cannot produce speech
- NON DOMINANT = APRAXIA AND HEMINEGLECT SYNDROME
Apraxia = patient can move muscles to do stuff, but don’t know how to
Hemineglect syndrome: all visual and sensory sensations on the contralateral side is neglected
E.g. if the left MCA is affected, the left optic radiations will be affected so the right visual field will be lost = right homonymous hemianopia.
PCA signs
Visual problems
- Homonymous hemianopia with macula sparring (as the MCA can still supply the region of the occipital lobe which is responsible for the macular)
- Prosopagnosia (can see people but not recognise them)
- Visual agnosia (patient can see but not interpret symbols e.g. letters)
Vertebrobasilar
Cerebellar signs
Reduced consciousness
Quadriplegia (paralysis of all 4 limbs - arms and legs) or hemiplegia
Lacunar stroke
Affects the small perforating branches to subcortical structures (e.g. internal capsule, basal ganglia, thalamus, pons)
- Unilateral weakness
- Pure sensory loss
- Ataxic Hemiparesis (cerebella and motor symptoms)
Investigations
FIRST LINE = Non-contrast CT head
- exclude haemorrhage
ECG = atrial fibrillation
Bloods tests =
- Glucose to rule out hypoglycaemia
- FBC - looking for polycythaemia
- ESR - raised in vasculitis
- U+E
- Cholesterol
- INR - if on WARFRIN
Management
FIRST LINE = Antiplatelet = Aspirin 300mg
- If treated with thrombolysis, start aspirin after 24 hours once haemorrhage is excluded
- continue until 2 weeks after the onset of stroke symptoms
Thrombolysis: If < 4.5 hours of symptoms onset and haemorrhage excluded on imaging = IV ALTEPLASE
SECONDARY PREVENTION =
- Clopidogrel 75mg daily lifelong is first line (after 2 weeks of aspirin 300mg)
- High dose statin: ATORVASTATIN 20-80mg usually 48 hours of the stroke
Complications
Deep vein thrombosis: due to immobility
Aspiration pneumonia: due to dysphagia
Neurological sequelae: such as weakness, impaired mobility, MCA syndrome and seizures
Requirement for nutritional support: such as nasojejunal feeding
Depression
