Stroke
Sudden focal neurological deficit from disrupted blood supply to the brain (ischaemic in the majority from vessel occlusion, haemorrhagic in the rest from vessel rupture), and telling the two apart with an urgent CT head is the single decision that determines whether thrombolysis can be given.
In a nutshell
Stroke is a sudden focal deficit from disrupted blood supply, ischaemic (occlusion) in most cases, haemorrhagic (rupture) in the rest, and only a CT head can tell them apart, which is why it is done before anything else.
Classic presentation
Sudden-onset unilateral facial droop, arm weakness and slurred speech (FAST) in a patient with vascular risk factors.
Key points
- CT head always comes before treatment: stroke type cannot be assumed clinically, and thrombolysis in a haemorrhagic stroke is dangerous.
- The ischaemic penumbra is salvageable tissue kept alive by collateral flow: thrombolysis and thrombectomy work by restoring flow before it infarcts, hence strict time windows.
- Bamford classification predicts the territory and prognosis from the clinical pattern of higher cortical dysfunction, hemianopia and motor/sensory deficit, without needing imaging.
- Hypoglycaemia is a key stroke mimic and must be excluded with a bedside glucose immediately.
- Aspirin is given once haemorrhage is excluded; anticoagulation for secondary prevention (for example in AF) is not started acutely.
First-line investigation
Non-contrast CT head: the single test that separates ischaemic from haemorrhagic stroke and determines eligibility for thrombolysis.
First-line management
Urgent CT head to exclude haemorrhage, then thrombolysis and/or thrombectomy within the time window if ischaemic, followed by aspirin.
Exam traps
- Thrombolysis is never given before a CT head has excluded haemorrhage, regardless of how classic the ischaemic picture looks.
- A normal early CT does not exclude ischaemic stroke; early ischaemic changes can be subtle and CT is mainly there to exclude blood.
- Hypoglycaemia can perfectly mimic a stroke and must be checked at the bedside before assuming a vascular cause.
Educational content pending clinical review. Not medical advice.