Neurology Neurology · High Yield

Stroke Types

Stroke is sudden focal neurological deficit caused by vascular pathology. Classification into ischaemic and haemorrhagic subtypes is essential because treatment is fundamentally different — thrombolysis is beneficial in ischaemic stroke but potentially fatal in haemorrhagic stroke.

✦ The Mnemonic

"Ischaemic Three, Haemorrhagic Two — Classify Before Treating"

Ischaemic: Thrombotic, Embolic, Lacunar · Haemorrhagic: Intracerebral haemorrhage, SAH

Th Thrombotic In-situ thrombus on atherosclerotic plaque; gradual onset; large vessel or small vessel

Em Embolic Clot from heart (AF, valves, LV thrombus) or proximal artery; sudden onset; maximal at onset

La Lacunar Small perforating artery occlusion; hypertension; pure motor, pure sensory, ataxic hemiparesis

ICH Intracerebral Haemorrhage Hypertension most common; blood-brain interface → oedema + mass effect; worse prognosis than ischaemic

SAH Subarachnoid Haemorrhage Berry aneurysm rupture (85%); thunderclap headache; CT first, LP if negative; nimodipine for vasospasm

📚 Clinical Breakdown

The TOAST classification of ischaemic stroke: Large artery atherosclerosis, Cardioembolic, Small vessel (lacunar), Other determined aetiology, Undetermined (cryptogenic). Cardioembolic is the most common single subtype — atrial fibrillation accounts for 15–20% of all ischaemic strokes and 50% of cardioembolic strokes.

Lacunar syndromes involve the internal capsule or brainstem perforators: pure motor hemiparesis (posterior limb of internal capsule), pure sensory stroke (thalamus), sensorimotor stroke, ataxic hemiparesis, clumsy hand-dysarthria. They carry a better prognosis than cortical strokes.

Management: ischaemic stroke within 4.5 hours → IV alteplase thrombolysis (exclude haemorrhage with CT first). LVO (large vessel occlusion) → mechanical thrombectomy up to 24 hours. Haemorrhagic stroke → reverse anticoagulation; BP control; neurosurgical assessment. Secondary prevention: AF-related → anticoagulation; non-cardioembolic → antiplatelet + statin + BP control.

Most common stroke Ischaemic (85%)

Most common ischaemic cause Cardioembolic (AF most common source)

Thrombolysis window 4.5 hours — CT first to exclude haemorrhage

SAH headache Thunderclap — worst headache ever, maximal at onset

⭐ Clinical Pearl

FAST campaign (Face drooping, Arm weakness, Speech difficulty, Time to call 999) identifies 88% of ischaemic strokes. The expanded BE-FAST (Balance, Eyes, Face, Arm, Speech, Time) adds posterior circulation features — balance disturbance and visual symptoms. Posterior fossa strokes are commonly missed because symptoms (vertigo, ataxia) are attributed to labyrinthine disease.

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