A warning sign, not a minor event
A transient ischemic attack (TIA) causes stroke symptoms that go away, usually within minutes. It is a warning: the risk of a full stroke is highest in the first 48 hours. The ABCD² score, published by Johnston and Rothwell in 2007, estimates that short-term risk.
The criteria
| Item | Finding | Points |
|---|---|---|
| Age | 60 or older | 1 |
| Blood pressure | ≥140/90 mmHg at first evaluation | 1 |
| Clinical features | Weakness on one side | 2 |
| Speech disturbance without weakness | 1 | |
| Duration | 60 minutes or more | 2 |
| 10 to 59 minutes | 1 | |
| Diabetes | Yes | 1 |
The total ranges from 0 to 7.
Worked example
A 67-year-old has slurred speech without weakness for 20 minutes, a blood pressure of 150/92 and no diabetes: 1 + 1 + 1 + 1 + 0 = 4, moderate risk.
Risk by score
| Score | Risk group | 2-day stroke risk | 90-day stroke risk |
|---|---|---|---|
| 0–3 | Low | about 1.0% | about 3.1% |
| 4–5 | Moderate | about 4.1% | about 9.8% |
| 6–7 | High | about 8.1% | about 17.8% |
These are figures from the original cohorts. With rapid evaluation and treatment, modern stroke rates after TIA are much lower, about 1.5% at 2 days, which shows how much urgent care helps.
Why guidelines no longer rely on the score alone
The ABCD² score misses some patients at high risk, such as those with atrial fibrillation or a severely narrowed carotid artery. The American Heart Association and other bodies therefore recommend urgent evaluation of every suspected TIA, ideally within 24 hours, with brain imaging (preferably MRI), vascular imaging of the neck and an ECG.
Treatment after a TIA
Depending on the cause: short-term dual antiplatelet therapy (aspirin plus clopidogrel or ticagrelor for 21 to 30 days in minor stroke or high-risk TIA), anticoagulation for atrial fibrillation, carotid surgery or stenting, statins and blood pressure control.
Recognizing a stroke
Remember BE FAST: Balance loss, Eyes (sudden vision loss), Face drooping, Arm weakness, Speech difficulty, Time to call 911. Even if symptoms disappear, call.
This calculator is for general information and education. It is not medical advice and does not replace the judgment of a doctor, nurse or pharmacist who knows the full clinical picture.