Stroke Flashcards
What is the difference between stroke and epilepsy in type of symptoms?
- Stroke - negative symptoms
2. Epilepsy - positive symptoms
What is a stroke?
Sudden interruption in the vascular supply of the brain resulting in focal neurological deficits lasting over 24 hours.
What are the causes of an ischaemic stroke?
- Atherothromboembolism from internal carotid
- Cerebral microangiopathy
- Carotid artery dissection (younger)
- Thrombophilia
- Venous sinus thrombosis
What are the three different types of stroke?
- Ischaemic (85%) - block in blood flow
- Intraparenchymal haemorrhagic (15%) - burst small blood vessel, reduction in blood flow
- Venous stroke (1%)
What are the causes of an intraparenchymal haemorrhagic stroke?
- HTN
2. Coagulopathy
What is the difference between intraparenchymal haemorrhagic stroke and a subarachnoid haemorrhage?
- SAH is intracerebral
2. SAH involves berry aneurysm of large vessel, IHS involves a burst small blood vessel
How does a venous stroke present?
- Raised ICP
2. Focal neurology and seizures
Why are the optic tracts less affected in strokes than other cortical functions?
They are in white matter, so only a large stroke would affect them.
What is the underlying pathophysiology of a haemorrhagic stroke?
- Hyaline arteriosclerosis and microaneurysm formation
2. Cerebral amyloid angiopathy of the small leptomeningeal vessels
What are the risk factors for developing a stroke?
HTN (leading cause), age, smoking, alcohol, diabetes, IHD, AF, PVD, COCP, hyperlipidaemia, coagulopathies.
What are the differentials for a stroke?
Head injury, hypoglycaemia, tumour, migraine, encephalopathy, encephalitis, MS, syncope.
What are the signs seen in a stroke from a cerebral infarct?
- Contralateral sensory loss - hemiplegia
- Hemiparesis - initially flaccid
- Pyramidal weakness - upper limb extensor weakness, lower limb flexor weakness
- Spasticity
- Hyperreflexia
- Dysphasia
- Homonymous hemianopia
What are the signs seen in a stroke from a brainstem infarct?
- Varied - including quadriplegia
2. Vision disturbances
What are the signs seen in a stroke from a lacunar infarct?
- Pure motor, ataxic, pure sensory, or mixed sensorimotor hemiparesis
- Dysarthria/clumsy hand
- Cognition/consciousness intact except in thalamic strokes
What are the signs seen in a haemorrhagic stroke?
Meningism, headache, coma within hours.
Why are Broca and Wernicke areas on the left in most peoples brains?
Because most people are left brain dominant
What are the non-dominant Broca and Wernicke areas responsible for?
- Broca - tone of speech
2. Wernicke - understanding non-verbal language
What is the effect of a unilateral temporal lobe infarction on hearing?
- No contralateral deafness as auditory fibres cross over
2. Patients cannot locate where sounds are coming from
What is the criteria for a partial vs a total anterior stroke?
All 3 = total, any 2 = partial:
- Unilateral weakness (+/- sensory deficit)
- Homonymous hemianopia
- Dysphasia
What is this a presentation of?
Contralateral hemiparesis and sensory loss - LEGS.
Anterior cerebral artery stroke
What is this a presentation of?
Contralateral hemiparesis and sensory loss - ARMS.
Contralateral homonymous hemianopia
Aphasia
Middle cerebral artery stroke
What is this a presentation of?
Contralateral homonymous hemianopia and macular sparing. Visual agnosia and cerebellar signs.
Posterior cerebral artery stroke
What is this a presentation of?
Ipsilateral CN III palsy
Contralateral weakness of upper and lower limb.
Weber’s stroke (branches of PCA that supply the midbrain)
What is this a presentation of?
Ipsilateral facial pain and temperature loss
Contralateral limb pain and temperature loss
Lateral medullary syndrome
Posterior inferior cerebellar artery stroke
What is this a presentation of?
Ipsilateral facial paralysis and deafness
Contralateral limb pain and temperature loss
Acute bilateral deafness and vertigo
Lateral pontine syndrome
Anterior inferior cerebellar stroke
What is the important differential to exclude in acute bilateral deafness and vertigo?
Anterior inferior cerebellar stroke
What examination should you perform on a suspected stroke patient?
- Look for xanthoma, stigmata of endocarditis, marfanoid appearance.
- Full neurological examination
What bloods should you order for a suspected stroke patient?
- FBC, ESR (vasculitis), U&Es + LFTs (metabolic cause of neurological impairment), clotting, glucose, lipids.
- Young stroke - lupus screen, HIV, ANA, dsDNA, ESR
- Consider - factor V Leiden, JAK2
What imaging should be performed on a suspected stroke patient?
- 24hr/7d ECG - look for AF
- CXR - signs of LVH from HTN and cancer
- Echo heart for emboli
- Doppler USS carotids - source of emboli, potential carotid endarterectomy if stenosis >70%
- CTA/MRI for posterior circulation stroke
What is the immediate management in resus for a suspected stroke patient?
- Protect airway
- Maintain homeostasis - BG, BP, sats
- Assess safe swallow, NBM if necessary
- Non-contrast CT within 1 hour
- Admit to stroke unit
What is the management of a suspected stroke patient once a haemorrhagic stroke has been ruled out on CT?
- Give aspirin 300mg if >4.5 hours from onset
- Thrombolysis with alteplase within 4.5 hours of onset of symptoms, re-do CT 24 hours later.
- If >4.5 hours then only aspirin loading dose.
- Start aspirin 300mg for 2 weeks - wait 24 hours after thrombolysis
- Thrombectomy if proximal large artery occlusion
- SALT, OT, PT input
What are the main contraindications for thrombolysis?
Major trauma/haemorrhage, surgery in past 2 weeks, LP in past week, ischaemic stroke in past 3 months, seizures at presentation, BP>185, INR>1.7
How effective is thrombolysis and what is the risk of complication?
- Helps 1 in 8 recover
2. 1 in 18 risk of bleed in the brain which can cause death
What is the management for a haemorrhagic stroke identified on CT?
- Reverse anticoagulation
- Lower BP to 140mmHg systolic
- Neurosurgery referral
- Hyperdense on CT brain
What is the primary prevention for stroke?
- Control HTN, DM, and lipids
- Quit smoking
- Anticoagulate in cardiac causes of stroke
What is the secondary prevention for ischaemic stroke?
- Aspirin 300mg for 2 weeks then switch to long term clopidogrel monotherapy.
- If clopidogrel not tolerated, aspirin and dipyridamole
What is the secondary prevention for ischaemic stroke in underlying AF?
- DOAC for non-valvular AF
2. Warfarin for valvular AF/significant CKD/metallic valves
What are the target results for antihypertensives and statins in the secondary prevention of a stroke?
- Antihypertensives - 130/80 BP
2. Statins - cholesterol <4, LDL <2
What advice do the DVLA give for driving after a stroke?
Not for 1 month, no need to inform DVLA
What is the prognosis of a stroke?
Less than 40% achieve full recovery.
How does a haemorrhagic vs ischaemic stroke show up on CT?
- Haemorrhagic - white/’hyperdense’ area
2. Ischaemic - dark area