Neurology

Stroke

Sudden focal neurological loss from arterial occlusion or vessel rupture: occlusion leaves a dying core around which viable brain can still be rescued, rupture makes any antithrombotic dangerous.

In a nutshell

Stroke is sudden focal neurological loss from cerebral infarction or haemorrhage, and only imaging separates them. Once intracranial haemorrhage is excluded, thrombolyse within 4.5 hours with blood pressure below 185/110 mmHg.

Classic presentation

Sudden right facial droop, right arm weakness and expressive dysphasia in an 80-year-old with atrial fibrillation, last seen well 2 hours ago.

Key points

The modified Rankin scale (mRS) grades function before the stroke; the National Institutes of Health Stroke Scale (NIHSS) grades the deficit. Both gate thrombectomy.
A negative FAST does not exclude stroke: sudden visual disturbance and cerebellar signs are missed. Treat as stroke if you suspect it.
NICE targets glucose at 4 to 11 mmol/litre; the national stroke guideline uses 5 to 15. Follow the hyperacute protocol and avoid hypoglycaemia.
Adults with type 1 diabetes and threatened or actual stroke need intravenous insulin and glucose under the hyperacute protocol.
Cerebral venous sinus thrombosis is anticoagulated even with secondary haemorrhage: full-dose heparin, then warfarin to an INR of 2 to 3.
Prosthetic valve with disabling cerebral infarction and haemorrhagic transformation risk: stop anticoagulation for 1 week and substitute aspirin 300 mg.
Do not start a statin immediately in acute stroke, but continue one the person is already taking.
Nasogastric feeding within 24 hours of admission if oral intake is unsafe, unless the person has had thrombolysis.
Rehabilitation should be at least 3 hours a day on at least 5 days a week, tailored to need.
High-intensity mobilisation means starting within 24 hours with at least 3 extra out-of-bed sessions. Sitting out of bed as the condition permits is not that.

First-line investigation

Capillary glucose, then immediate non-enhanced CT head, adding CT angiography from aortic arch to skull vertex if thrombectomy is possible.

Management

Recognise it, time it, exclude the mimic

Use FAST (Face, Arm, Speech, Time) outside hospital and ROSIER (Recognition of Stroke in the Emergency Room) in the emergency department. Record the last known well time.^1,2,3
Check capillary glucose first. Below 4.0 mmol/L give 15 to 20 g of rapid-acting carbohydrate if alert, then recheck after 10 to 15 minutes.^1,7
Admit directly to a specialist acute stroke unit. Nil by mouth until the swallow screen is done. Oxygen only if saturation falls below 95%.^1,2
Screen swallowing within 4 hours of arrival, before any oral food, fluid or medicine. If abnormal, specialist assessment within 24 hours, at most 72.^1,2

Image within the hour

Immediate non-enhanced CT if thrombolysis or thrombectomy is possible, on anticoagulants, bleeding tendency, GCS below 13, progressive symptoms, papilloedema, neck stiffness, fever, or severe headache at onset.¹
Otherwise scan within 24 hours. Aim to image everyone within 1 hour of arrival. Add CT angiography if thrombectomy is possible, plus perfusion beyond 6 hours.^1,2

Reperfuse, then antiplatelet

Alteplase 900 micrograms/kg intravenously, maximum 90 mg: 10% as a bolus, the rest over 60 minutes. Start within 4.5 hours, once haemorrhage is excluded.^4,9,1
Tenecteplase is the single-bolus alternative: 15 mg below 60 kg, rising to 25 mg at 90 kg or more, also within 4.5 hours.^5,10
Reduce blood pressure below 185/110 mmHg before thrombolysis. Otherwise do not lower it in acute ischaemic stroke unless there is a hypertensive emergency.^1,2,9
Thrombectomy: within 6 hours for proximal anterior circulation occlusion; 6 to 24 hours if tissue is salvageable; consider up to 24 hours for basilar or posterior cerebral artery.¹
NICE uses pre-stroke mRS below 3 and NIHSS above 5. National guidance is stricter and adds ASPECTS; refer and let the stroke team apply its pathway.^1,2
Aspirin 300 mg within 24 hours once haemorrhage is excluded, orally or by enteral tube, then 300 mg daily for 2 weeks. After thrombolysis, wait 24 hours.^1,2,11

Haemorrhage and the neurosurgical calls

Intracerebral haemorrhage: reverse warfarin with prothrombin complex concentrate (PCC) and intravenous vitamin K, idarucizumab for dabigatran, 4-factor PCC for factor Xa inhibitors.^1,2
For systolic 150 to 220 mmHg, NICE targets 140 or lower; national guidance targets 130 to 139. Use the hyperacute protocol and avoid a precipitous fall.^1,2
Decompressive hemicraniectomy within 48 hours if NIHSS is above 15, consciousness is reduced, and at least 50% of the middle cerebral artery (MCA) territory is infarcted.^1,2

TIA and minor stroke

Suspected TIA: aspirin 300 mg immediately and specialist assessment within 24 hours. Do not use ABCD2, and do not order a CT head.^1,11,2
Within 24 hours and at low bleeding risk: clopidogrel 300 mg then 75 mg daily, plus aspirin 300 mg then 75 mg daily for 21 days.^2,12,11
Then clopidogrel 75 mg alone. The alternative is ticagrelor 180 mg then 90 mg twice daily, with aspirin for 30 days rather than 21.^2,13,12

Prevent the next one

Long term: clopidogrel 75 mg daily, or aspirin 75 mg daily if clopidogrel is not tolerated. Do not continue dual antiplatelet treatment without a separate indication.^8,12,11
Atorvastatin 80 mg daily targeting LDL-cholesterol below 1.8 mmol/L, and a clinic systolic blood pressure below 130 mmHg.^8,14
Symptomatic carotid stenosis of 50% to 99% by NASCET criteria: refer urgently for endarterectomy. Below 50%, best medical treatment only.^1,8
Rehabilitation at least 3 hours a day on at least 5 days a week. Safety-net: call 999 for any new FAST symptoms.^6,3

Exam traps

A normal early CT does not exclude ischaemic stroke. What it excludes is haemorrhage, which is what you need before aspirin or thrombolysis.
ABCD2 is still widely taught, but NICE says do not use it: it fails to separate low-risk from high-risk TIA.
Do not request a CT head for suspected TIA unless another diagnosis is suspected. MRI, after specialist assessment, is the right scan.
Posterior circulation stroke presents with vertigo, ataxia, diplopia or dysarthria and is FAST-negative.
Oxygen in acute stroke starts only below 95% saturation, a stroke-specific figure. Do not carry across the threshold you learned for other acute conditions.
Aspirin is delayed 24 hours after thrombolysis. In suspected TIA it is given immediately.
Reversing a direct oral anticoagulant (DOAC) in order to thrombolyse is not recommended.
In disabling stroke with atrial fibrillation, give aspirin 300 mg for 2 weeks first. Non-disabling stroke or TIA is anticoagulated once bleeding is excluded.
The same carotid artery scores differently under NASCET and ECST criteria, so the report must state which was used.

Illustrations

Vascular territories and the Oxfordshire (Bamford) classificationDiagram of the anterior, middle and posterior cerebral artery territories mapped against the Oxfordshire Community Stroke Project categories. These are total anterior circulation syndrome (TACS), partial anterior circulation syndrome (PACS), posterior circulation syndrome (POCS) and lacunar syndrome (LACS).PassFinals · original

CT head in acute strokeNon-contrast CT of the head performed in acute stroke.Hellerhoff, Wikimedia Commons · CC-BY-SA-3.0

Ischaemic core and penumbraPerfusion diagram showing an infarcted core surrounded by salvageable penumbra sustained by collateral flow, shrinking over time.PassFinals · original

Key sources

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.