🧠 What is a TIA?
A Transient Ischaemic Attack (TIA) is a brief episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischaemia, without acute infarction, that resolves completely (typically within 1 hour, always <24 hours).
A TIA is a MEDICAL EMERGENCY. The risk of stroke in the first 48 hours after TIA is approximately 10–15%. Without urgent treatment, up to 10% of TIA patients will have a disabling stroke within 2 days. TIA is a warning — "the brain is sending a fire alarm."
How TIA Differs from Ischaemic Stroke
| Feature | TIA | Ischaemic Stroke |
|---|
| Duration of symptoms | Usually <1 hour; always <24 hours | Persists beyond 24 hours |
| MRI evidence of infarction | No acute infarction | Acute DWI-positive lesion |
| Disability | Full neurological recovery | Residual deficit |
| Thrombolysis | NOT indicated (no infarction) | May be indicated (alteplase within 4.5h) |
Classic TIA Presentations
- Amaurosis fugax: Transient monocular blindness — "curtain coming down over one eye" — ipsilateral carotid disease until proven otherwise
- Hemispheric TIA: Contralateral arm/leg weakness, face droop, speech disturbance (dysphasia/dysarthria) — middle cerebral artery territory
- Posterior circulation TIA: Diplopia, vertigo, dysphagia, ataxia, bilateral visual disturbance — vertebrobasilar territory
Mimics to consider (not TIA): Migraine aura (positive visual symptoms, spreads slowly), hypoglycaemia (check BGL immediately in ALL cases), focal seizure (Todd's paresis), MS relapse, syncope. Always check blood glucose first.
Immediate Investigations
- Blood glucose — exclude hypoglycaemia (FIRST action)
- FBC, U&E, coagulation screen, lipid profile, HbA1c
- 12-lead ECG — look for atrial fibrillation (cardioembolic source)
- Brain MRI with DWI (preferred) or CT — exclude haemorrhage, identify acute ischaemia
- Carotid Doppler ultrasound — within 24 hours if ABCD² ≥4 or carotid territory TIA
- Echocardiogram — if cardioembolic source suspected (AF, structural heart disease)
- 24-hour Holter monitor — if paroxysmal AF suspected
📊 ABCD² Score — Stroke Risk After TIA
The ABCD² score estimates the short-term risk of stroke after TIA. While no longer used in isolation to determine admission vs discharge (specialist assessment is now recommended for all), it guides urgency of workup and specialist referral.
⭐ ABCD² Score Components
A — Age ≥60 years+1
B — Blood pressure at presentation: systolic ≥140 or diastolic ≥90+1
C — Clinical features: unilateral weakness+2
C — Clinical features: speech disturbance only (no weakness)+1
D — Duration: ≥60 minutes+2
D — Duration: 10–59 minutes+1
D — Duration: <10 minutes+0
² — Diabetes (known diagnosis)+1
Score Interpretation
| Score | Risk Category | 2-Day Stroke Risk | Action |
|---|
| 6–7 | High | ~8% | Admit/urgent neurology within hours |
| 4–5 | Moderate | ~4% | See TIA clinic within 24 hours |
| 0–3 | Low | ~1% | See TIA clinic within 24–48 hours |
Modern practice: Current NICE, ESO, and AHA/ASA guidelines recommend ALL patients with suspected TIA be assessed urgently by a stroke specialist — ideally within 24 hours regardless of ABCD² score. ABCD² alone is insufficient to safely discharge without specialist review.
High-Risk Features Requiring Same-Day Assessment
- Multiple TIAs in the past 7 days (crescendo TIA) — very high stroke risk
- Atrial fibrillation detected on ECG
- Known carotid stenosis
- Symptoms still present (consider thrombolysis if acute stroke)
- On anticoagulation (suggest cardioembolic source despite treatment)
🏥 Acute TIA Management
Step 1: Immediate Actions
- Check and correct blood glucose (hypoglycaemia is the most important mimic)
- 12-lead ECG — identify atrial fibrillation
- IV access and bloods: FBC, UE, glucose, lipids, coagulation
- CT/MRI brain — exclude haemorrhage before antiplatelet therapy
- BP recording — do NOT aggressively lower BP acutely (different to established ischaemic stroke protocol)
Do NOT give antiplatelets if haemorrhage has NOT been excluded by imaging. If CT shows intracerebral haemorrhage, antiplatelets are contraindicated.
Step 2: Antiplatelet Loading (Once Haemorrhage Excluded)
DUAL ANTIPLATELET THERAPY (DAPT):
Aspirin 300 mg loading dose PLUS Clopidogrel 300–600 mg loading dose
Then: Aspirin 75 mg + Clopidogrel 75 mg daily for 21 days
After 21 days: Clopidogrel 75 mg daily monotherapy long-term
(POINT and CHANCE trials evidence)
Alternative: Aspirin + Ticagrelor (THALES trial) for high-risk TIA. Ticagrelor 180 mg loading then 90 mg twice daily + Aspirin for 30 days.
If AF identified: Anticoagulation (DOAC or warfarin) is indicated INSTEAD of antiplatelets. Do NOT dual-treat with antiplatelet + anticoagulant without specialist guidance.
Step 3: Carotid Assessment
- Carotid Doppler ultrasound within 24 hours for carotid territory TIA (amaurosis fugax, hemispheric symptoms)
- If carotid stenosis ≥50% ipsilateral to TIA symptoms: urgent referral for carotid endarterectomy (CEA) or stenting
- CEA should be performed within 48–72 hours if symptomatic stenosis ≥70% — this dramatically reduces stroke risk (benefit up to 16× greater if performed within 2 weeks)
Step 4: BP Management
- Target BP <130/80 mmHg long-term
- Start antihypertensive (ACEi/ARB ± thiazide diuretic) after acute phase
- Do not aggressively lower BP in the acute TIA setting — may reduce cerebral perfusion pressure
Step 5: Statin Therapy
High-intensity statin: Atorvastatin 40–80 mg daily for ALL TIA patients regardless of baseline cholesterol. Statins reduce stroke recurrence risk.
🛡️ Secondary Stroke Prevention
ABCDE of Secondary Prevention
| Letter | Intervention | Target / Notes |
|---|
| A | Antiplatelet / Anticoagulation | As above; DOAC if AF (not warfarin in most); avoid aspirin + DOAC |
| B | Blood pressure control | Target <130/80; ACEi/ARB + thiazide first-line |
| C | Cholesterol (statin) | Atorvastatin 40–80 mg; LDL-C target <1.8 mmol/L (<70 mg/dL) |
| D | Diabetes management | HbA1c <48 mmol/mol (6.5%); metformin first-line |
| E | Exercise + lifestyle | 150 min/week moderate exercise; quit smoking; low alcohol; Mediterranean diet |
Atrial Fibrillation and TIA
AF is a major stroke risk factor. Cardioembolic strokes from AF are typically larger and more devastating than atherosclerotic strokes. Any new AF found after TIA requires anticoagulation unless contraindicated.
- CHA₂DS₂-VASc score used to quantify stroke risk in AF
- Score ≥2 in men, ≥3 in women = anticoagulate (most TIA patients meet this threshold)
- DOACs (apixaban, rivaroxaban, dabigatran) preferred over warfarin in non-valvular AF
- Anticoagulation typically started within 1–2 weeks after TIA (4–14 day rule: sooner for TIA/minor stroke, later for major stroke with haemorrhagic transformation risk)
Carotid Endarterectomy (CEA)
- Indicated for symptomatic carotid stenosis 50–99%
- Greatest benefit if performed within 2 weeks of TIA
- Reduces ipsilateral stroke risk by ~50% at 5 years
- Carotid stenting: alternative for patients unfit for surgery
Lifestyle Modification Advice
- Smoking cessation — reduces stroke risk 50% within 1 year
- Mediterranean diet: olive oil, vegetables, fish, nuts; reduced processed food
- Avoid excess alcohol (>14 units/week associated with increased AF and haemorrhagic stroke risk)
- Regular aerobic exercise (150 min/week moderate intensity)
- Weight management (BMI 18.5–25 kg/m²)
Driving Restrictions (UK/GCC Context)
- Patients must be advised NOT to drive after TIA until clinically assessed
- In the UK: DVLA advises no driving for 1 month after TIA
- GCC countries: follow national MOH driving regulations — advise patients to inform licensing authority