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ABCD² Score for TIA

ABCD² (0–7) estimates early stroke risk after TIA from Age, Blood pressure, Clinical features, Duration and Diabetes. 2-day stroke risk in the derivation cohorts: 0–3 low (1.0%), 4–5 moderate (4.1%), 6–7 high (8.1%).

  • Age (years)
  • First systolic BP after TIA (mmHg or kPa)
  • First diastolic BP after TIA (mmHg or kPa)
  • Clinical features: Unilateral weakness (2); Speech disturbance without weakness (1); Other symptoms (0)
  • Duration of symptoms: ≥ 60 minutes (2); 10–59 minutes (1); < 10 minutes (0)
  • Diabetes (yes/no, +1)
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Interpretation

ResultMeaning
0–3Low risk: 2-day stroke 1.0%
4–5Moderate risk: 2-day stroke 4.1%
6–7High risk: 2-day stroke 8.1%

Formula

Age ≥60: 1 · BP ≥140/90 at first assessment: 1 · Unilateral weakness 2, speech disturbance without weakness 1 · Duration ≥60 min 2, 10–59 min 1 · Diabetes 1

Clinical pearls

  • Current guidelines recommend urgent specialist assessment and imaging for all suspected TIA; a low ABCD² does not exclude carotid stenosis, AF or other high-risk mechanisms.
  • Derived and validated in patients with clinically diagnosed TIA seen within days of the event; not for completed stroke.

Examples

abcd2 65 yo bp 150/85 unilateral weakness 70 minutes diabeticTIA risk for a 50 year old with 15 minutes of slurred speech, BP 120/70, no diabetes

FAQ

What does an ABCD² of 4 mean?

Moderate risk: about 4.1% 2-day stroke risk in the derivation cohorts.

Should ABCD² decide whether to admit a TIA patient?

Not alone. Guidelines now favour rapid evaluation (imaging, vascular studies, ECG) for every TIA regardless of score.

Evidence

  1. Johnston SC et al. Validation and refinement of scores to predict very early stroke risk after transient ischaemic attack. Lancet 2007;369:283–92.

Neurology · Reviewed 2026-10-14 · Methodology