STROKE

Stroke

This is a sudden onset of a neurological deficit.

Some differential diagnoses and typical outline evidence

Cerebral infarction	Suggested by: onset over minutes to hours of hemiaparesis or major neurological defect that lasts >24 hours.
	Confirmed by: CT scan appearing after days.
	Management:
Transient cerebral ischaemic attack due to carotid artery stenosis etc. (see below)	Suggested by: onset over seconds to minutes of a neurological deficit that is improving already.
	Confirmed by: deficit resolving within 24 hours.
	Management:
Cerebral embolus due to atheroma, atrial fibrillation, myocardial infarction	Suggested by: onset over seconds of hemiaparesis or other neurological defect that lasts >24 hours.
	Confirmed by: CT scan and lumbar puncture showing little change originally. Evidence of a potential source for an embolus.
	Management:
Cerebral haemorrhage due to atheromatous degeneration, cerebral tumour	Suggested by: onset over seconds of hemiaparesis or major neurological defect that lasts >24 hours.
	Confirmed by: CT showing high attenuation ± ‘low’ (dark) ‘oedema’ area ± high density ‘blood’ in ventricles.
	Management:
Subdural haemorrhage due to blunt head injury	Suggested by: onset over hours, days or weeks of a fluctuating hemiaparesis following history of head injury or fall especially in elderly or alcoholic.
	Confirmed by: CT showing low attenuation parallel to skull if chronic but high attenuation if acute.
	Management:
Extradural haemorrhage due to skull fracture lacerating middle meningeal artery	Suggested by: onset over minutes or hours of confusion, disturbed consciousness and hemiaparesis after ‘lucid interval’ of hours following head injury.
	Confirmed by: CT head showing high attenuation adjacent to skull ± hyper-density ± dark ‘oedema’ ± midline shift.
	Management:
Subarachnoid haemorrhage from berry aneurysm	Suggested by: sudden onset over seconds of headache ± disturbance of consciousness (usually under 45 years of age), neck stiffness.
	Confirmed by: CT head showing high attenuation area on surface of brain. Lumbar puncture showing blood.
	Management:
Cerebellar stroke	Suggested by: sudden onset of ataxia
	Confirmed by: MRI scan (CT head poorly visualises hind brain).
Pontine stroke	Suggested by: sudden loss of consciousness. Cheyne–Stokes breathing (speeding up and slowing down over minutes), pin-point pupils, hemiparesis and eyes deviated towards paresis.
	Confirmed by: above clinical findings ± MRI scan.