Stroke Flashcards
What makes up the anterior circulation of the brain?
ACA, MCA, posterior communicating artery
What makes up the posterior circulation?
PCA + joins anterior via posterior communicating
What does the ACA supply?
frontal and parietal lobe
What does the MCA supply?
lateral brain hemisphere including internal capsule and basal ganglia, most common site of infarction
- internal capsule - large number of motor and sensory fibres travel to and from the cortex
- basal ganglia - motor control, learning, executive functions
What does the PCA supply?
- occipital lobe and inferior proportion of temporal lobe, and thalamus
- thalamus - relay motor, sensory signals to cerebral cortex, regulate sleep, alertness etc
What is a stroke?
serious life-threatening medical condition that happens when the blood supply to part of the brain is cut off
- ischaemia: thrombosis, embolism
- haemorrhage
What is a TACS?
total anterior circulation stroke
- unilateral weakness +/- sensory deficit within face, arm or leg, homonymous hemianopia, higher cerebral dysfunction
*ACA or MCA
What is PACS?
partial anterior circulation stroke
- 2/3 of unilateral weakness +/- sensory deficit within face, arm or leg, homonymous hemianopia, higher cerebral dysfunction
*ACA or MCA
What is a lacunar stroke?
- deep perforating arteries like lenticulostriate , which supply thalamus, basal ganglia or pons
- pure motor hemiparesis, pure sensory, ataxic hemiparesis, dysarthria-clumsy hand syndrome, sensorimotor
What is POCS?
posterior circulation stroke
- vertebrobasilar arteries
- brain stem or cerebellar syndrome, loss of consciousness, isolated homonymous hemianopias
What are the symptoms of Webers syndrome?
(branches of the posterior cerebral artery that supply the midbrain)
Ipsilateral CN III palsy
Contralateral weakness of upper and lower extremity
Posterior inferior cerebellar artery (lateral medullary syndrome, Wallenberg syndrome)?
ipsilateral Horner’s syndrome, ipsilateral loss of pain and temperature sensation on the face
contralateral loss of pain and temperature sensation over the contralateral body
What are the symptoms of Anterior inferior cerebellar artery (lateral pontine syndrome)?
Symptoms are similar to Wallenberg’s (see above), but:
Ipsilateral: facial paralysis and deafness
What are some risk factors for haemorrhagic stroke?
age
hypertension
arteriovenous malformation
anticoagulation therapy
What are some risk factors for ischaemic strokes?
General risk factors for cardiovascular disease
age
hypertension
smoking
hyperlipidaemia
diabetes mellitus
Risk factors for cardioembolism
atrial fibrillation
How might a stroke present?
- sudden onset of neurological symptoms - vascular cause
- asymmetrical
- common
- limb weakness
- facial weakness
- dysphasia (speech disturbance)
- visual field defects
- sensory loss
- ataxia and vertigo (posterior circulation infarction)
How might you differentiate haemorrhagic from ischaemic stroke?
unable to tell without CT head!
How might you assess a stroke?
Face - ‘Has their face fallen on one side? Can they smile?’
Arms - ‘Can they raise both arms and keep them there?’
Speech - ‘Is their speech slurred?’
Time - ‘Time to call 999 if you see any single one of these signs.’
What scoring system might you use in hospital?
National institutes of health stroke scales
*for clinical outcome
What differentials might you consider in stroke patients?
- Toxic/ metabolic - hypoglycaemia, drug, alcohol consumption
- neuro - seizure, migraine, Bell’s palsy
- space occupying lesion - tumour, haematoma
- infection - meningitis/ encephalitis, systemic infection with decompensation of old stroke
- syncope - extremely uncommon presentation of TIA
- non-organic - functional neuro disorders
What major investigations might you consider in stroke patients?
CT head - ischaemic or haemorrhagic
*if normal treat as ischaemic as may not show initially
bedside, bloods, imaging
special - echo, carotid doppler, 24h tape, young stroke screen
What is the management for haemorrhagic stroke?
- Anticoagulants (e.g. warfarin) and antithrombotic medications (e.g. clopidogrel) should be stopped to minimise further bleeding + reverse anticoag
- BP control
- larger
- decompressive hemicraniectomy
- suboccipital craniotomy for posterior fossa bleeds
What is the management for ischaemic stroke?
thrombolysis - synthetic tissue plasminogen activator (alteplase)
WITHIN 4.5h
mechanical thrombectomy
What are the contraindications for thrombolysis?
previous intracranial haem, seizure at onset of stroke, intracranial neoplasm, suspected SAH, 3m previous stroke or traumatic brain injury, 3w preceding GI haem, pregnancy, oesophageal varices, uncontrolled HTN >200/120
What is the indication for thrombectomy?
- removal of thrombus from vessel
- offer within 6h of symptom onset with IV thrombolysis (4.5h window)
- offer to those known to be well between 6-24h previously (wake-up strokes)
- location specific and dependent on potential to salvage brain tissue according to CT
What other management considerations should you make?
- blood glucose, hydration, oxygen saturation and temperature - within normal limits
- blood pressure should not be lowered in the acute phase unless “hypertensive encephalopathy”
- aspirin 300mg orally or rectally if haemorrhagic excluded
- AF - anticoag not until haemorrhage excluded and not until 14 days passed from onset of ischaemic stroke
- cholesterol >3.5 mmol/l commenced on a statin, after 48h due to haemorrhagic transformation risk
