11.4 Stroke Flashcards
What are the symptoms and signs of stroke?
Headache
Acute onset of neurological symptoms: dizziness or balance disturbance, visual, hearing, speech or language abnormalities, muscle weakness or incoordination, swallow disturbance
Altered consciousness
What are the DD for stroke
Intracranial tumour or infection Seizure Demyelination Non occlusive, non haemorrhagic cerebrovascular disorder, hypoglycaemia Psychiatric disorder
What determines the symptoms?
Location and size of occluded blood vessel
Duration of occlusion
Potential for collateral blood supply
What is the normal blood flow and at what level will you see deficits?
Normal is 50-60ml/100g/min but the brain can cope with down to 20
10-20 you will have symptoms - stroke evolution, TIA and reversible ischaemic deficit
What is the infarct core and penumbra?
Core = region where the artery supplies and this region will die
Penumbra = area around the core where there is enough collateral blood supply so the function will decrease but not die - there will be symptoms but these can be reversed - this is the area that you really want to save
What are the causes of arterial occlusion and the risk factors?
Atherosclerosis: hypertension, hyperlipidemia, obesity, smoking, diabetes
Cardiac thromboembolism: atrial fibrillation, MI, cardiac valvular lesion, endocarditis
Pro-coagulant state: Protein C or S def, prothrombin G mutation, antithrombin III def, OCP
Arterial injury: penetrating injury, arterial dissection
Iatrogenic: invasive procedures
What are the causes of intracranial haemorrhage?
Vascular morphology: AV malformation, arteriovenous fistulaem cavernous malformation
Vascular micropathology: hyaline arteriosclerosis, amyloid angiopathy
Impaired coagulation
Hypertension
What is the presentation of a middle cerebral artery occlusion?
Face/arm weakness on C/L side, relative sparing of teh leg
Global aphasia if dominant hemisphere
What is the presentation of a anterior cerebral artery occlusion?
C/L leg weakness/numbness (may involve face/arm if recurrent artery), may have incontinence
What is the presentation of posterior cerebral artery occlusion?
Cortical homonymous hemianopia, macular sparing
Memory impairment if significant temporal lobe envolvement
Alexia if dominant hemisphere
Webers syndrome (C/L hemiplegia) if proximal
What will you get in a Basilar artery occlusion?
Loss of consciousness or locked in syndrome
Gaze abnormalities, facial anasthesia
What will you get with vertebral artery/PICA occlusion?
Dizziness, ataxia on I/L side (cerebellar)
Lateral medullary syndrome