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ukmla 2026

Transient Ischaemic Attack

Transient episode of focal neurological dysfunction caused by cerebral ischaemia without infarction, resolving within 24 hours — a medical emergency and warning of imminent stroke

Review date
reviewed 2026-04-05
Reading time
7 min read
Author
Dr Kola Tytler MBBS CertHE MBA MSt MRCGP
Neurologycommonacute
On this page
Condition details
Neurology
common
7 min read
reviewed 2026-04-05
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About This Page

This is a clinician-written, evidence-based summary aligned to the 2026 MLA Content Map. It is intended for medical students and junior doctors preparing for the UKMLA. Always cross-reference with NICE guidance, local protocols, and clinical judgement.

Key points

  • TIA = transient focal neurological deficit resolving within 24 hours with NO infarction on imaging
  • TIA is a MEDICAL EMERGENCY — high early stroke risk (up to 10% within 7 days without treatment)
  • Immediate aspirin 300 mg and urgent specialist assessment within 24 hours of symptom onset
  • Do NOT use ABCD2 score to determine urgency of referral — all TIAs need urgent assessment
  • Secondary prevention: clopidogrel 75 mg lifelong, statin, BP control; anticoagulation if AF

Overview

A transient ischaemic attack (TIA) is defined as a transient episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischaemia without acute infarction. The modern tissue-based definition requires absence of infarction on imaging (DWI MRI). TIAs most commonly result from thromboembolism — either from large artery atherosclerosis (carotid stenosis) or cardioembolism (atrial fibrillation). Small vessel disease (lacunar) is another important mechanism. TIA is a critical warning sign: the risk of stroke is highest in the first 48 hours and up to 10% within 7 days without treatment.

Epidemiology

The UK incidence of TIA is approximately 50 per 100,000 per year. It is more common in older adults, men, and those with cardiovascular risk factors. Key risk factors mirror those for ischaemic stroke: hypertension, atrial fibrillation, diabetes, hyperlipidaemia, smoking, and carotid artery stenosis. Up to 15% of all ischaemic strokes are preceded by a TIA, and early recognition and treatment significantly reduce subsequent stroke risk.

Clinical Features

Symptoms
Sudden-onset unilateral weakness or numbness of face, arm, or leg (resolves fully)
Speech disturbance: dysphasia (expressive/receptive) or dysarthria
Amaurosis fugax: transient monocular visual loss (like a curtain descending) — retinal ischaemia from ICA disease
Homonymous hemianopia (transient visual field loss)
Posterior circulation: vertigo, diplopia, ataxia, bilateral visual loss, dysarthria, bilateral limb weakness
Symptoms typically last minutes to 1–2 hours — by definition resolve within 24 hours
Signs
Often completely normal by the time of assessment (symptoms have resolved)
Carotid bruit (suggests carotid stenosis — though absence does not exclude it)
Irregular pulse (atrial fibrillation)
Hypertension
If focal signs are STILL PRESENT at assessment, manage as acute stroke

Investigations

First-line
Urgent specialist assessmentWithin 24 hours of symptom onset — in a TIA clinic or acute stroke service (NICE NG128)
BloodsFBC, U&Es, glucose, lipid profile, HbA1c, coagulation screen, ESR/CRP
ECGScreen for atrial fibrillation — present in ~15% of TIA patients
Second-line
MRI brain (DWI)To confirm no acute infarction (true TIA vs minor stroke). Perform same day if available after specialist assessment
Carotid Doppler ultrasoundUrgent — if anterior circulation TIA, assess for carotid stenosis. If ≥50% symptomatic stenosis, refer urgently for endarterectomy
Prolonged cardiac monitoring24-72 hour Holter or longer-term monitoring to detect paroxysmal AF
Specialist
CT angiographyIf Doppler equivocal or posterior circulation TIA suspected
EchocardiographyIf cardioembolic source suspected — especially in young patients or those without conventional risk factors

Management

NICE NG128 (Stroke and TIA in over 16s), 2019/2022
1
Immediate management
  • Aspirin 300 mg immediately (after haemorrhage excluded — CT only if alternative diagnosis suspected)
  • Refer URGENTLY for specialist assessment within 24 hours of symptom onset
  • Do NOT use ABCD2 score to triage urgency (NICE 2019) — all TIAs are urgent
  • If symptoms still present, manage as acute stroke (thrombolysis pathway)
2
Secondary prevention
  • Clopidogrel 75 mg OD lifelong (antiplatelet of choice per NICE)
  • Alternative if clopidogrel not tolerated: aspirin 75 mg + modified-release dipyridamole 200 mg BD
  • Atorvastatin 20–80 mg (high-intensity statin)
  • BP target: <130/80 mmHg
  • If AF confirmed: switch from antiplatelet to DOAC anticoagulation
3
Carotid intervention
  • If symptomatic carotid stenosis 50–99% (NASCET criteria): urgent carotid endarterectomy ideally within 2 weeks of TIA
  • Carotid stenting may be considered if endarterectomy is contraindicated
4
Lifestyle and driving
  • Smoking cessation, regular exercise, healthy diet, moderate alcohol
  • DVLA: must not drive for 1 month after TIA (Group 1). Group 2: must not drive for 1 month and must have no functional deficit

Complications

  • Stroke: Risk is highest in first 48 hours. Up to 10% within 7 days without treatment. Early treatment reduces 90-day stroke risk by ~80%
  • Recurrent TIA: Ongoing risk if underlying cause not addressed (particularly carotid stenosis and AF)
  • Anxiety and psychological impact: Fear of stroke — provide reassurance alongside clear follow-up plan
UKMLA Exam Tips
  • 1TIA is a MEDICAL EMERGENCY — urgent specialist assessment within 24 hours (not 7 days)
  • 2ABCD2 score should NOT be used to determine urgency of referral (NICE 2019)
  • 3Amaurosis fugax (transient monocular blindness) = retinal TIA = ipsilateral ICA disease
  • 4Aspirin 300 mg immediately, then switch to clopidogrel 75 mg for long-term secondary prevention
  • 5Carotid endarterectomy: symptomatic stenosis 50–99%, ideally within 2 weeks
  • 6If symptoms are STILL PRESENT = stroke, not TIA — manage as acute stroke
  • 7Posterior circulation TIA: vertigo + ataxia + diplopia ± bilateral symptoms — do not dismiss as isolated vertigo

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Verified Sources & References

NICE NG128 — Stroke and TIA in over 16s
NICE CKS — Stroke and TIA
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