How TIA is tested on Step 1

Transient focal symptoms plus a vascular risk factor.

TIASudden focal deficitNegative symptoms: weakness, numbness,vision lossMatches one vascular territoryResolves fully, usually within an hourNo infarct on MRIMimicsHypoglycemia: check glucose firstSeizure with Todd paralysisMigraine aura: spreading positivesymptomsSyncope: global, not focalPeripheral vertigovs
TIA vs mimics. Positive symptoms (flashing lights, tingling that spreads) favor migraine or seizure.

Risk stratification

The ABCD2 score estimates short-term stroke risk.

FeaturePoints
Age ≥ 60 years1
Blood pressure ≥ 140/90 mm Hg at presentation1
Clinical: unilateral weakness (2) or speech disturbance without weakness (1)1–2
Duration ≥ 60 minutes (2) or 10–59 minutes (1)1–2
Diabetes1

Higher scores mean higher short-term stroke risk, but every TIA needs prompt evaluation.

Finding the source

Look at the carotids and the heart.

GlucoseRule out hypoglycemia, a common mimicBrain MRIDiffusion imaging confirms or excludes infarctionCarotid imagingDuplex ultrasound or CT/MR angiography for stenosisHeart rhythmECG and monitoring for paroxysmal atrialfibrillationEchocardiogramThrombus, valve disease, patent foramen ovale
TIA workup. Also check lipids and HbA1c to target risk factors.

Prevention

Match therapy to the mechanism.

  • Atherosclerotic or small-vessel source: antiplatelet therapy (aspirin; short-term aspirin plus clopidogrel after high-risk TIA), high-intensity statin, blood pressure and diabetes control, smoking cessation.
  • Cardioembolic source (atrial fibrillation): anticoagulation (DOAC or warfarin) rather than antiplatelet therapy.
  • Symptomatic carotid stenosis of 70–99%: carotid endarterectomy (or stenting in selected patients), ideally within 2 weeks.

Worked example

Link the eye to the carotid.

functions Worked example — a curtain over one eye

A 68-year-old smoker had 5 minutes of painless vision loss in the right eye, "like a curtain coming down," that fully resolved. A right carotid bruit is heard. What is the likely source, and what test comes next?

  1. Brief, painless, one-eyed vision loss is amaurosis fugax.
  2. The ophthalmic artery is the first branch of the internal carotid, so emboli from carotid plaque reach the retina.
  3. The bruit supports right internal carotid stenosis.
  4. Carotid duplex ultrasound measures the stenosis; 70–99% symptomatic stenosis warrants endarterectomy.

Answer. Emboli from right internal carotid stenosis; obtain carotid duplex ultrasound.