ABCD2 Score: Estimates the risk of stroke within 2 days following a Transient Ischemic Attack (TIA).
Age ≥ 60 years (+1)
Elevated BP (≥ 140/90 mmHg) at presentation (+1)
Clinical Features
Duration of Symptoms
History of Diabetes (+1)
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Patients presenting with a suspected Transient Ischemic Attack (TIA) based on clinical history (typically focal neurologic deficit resolving within 24 hours)
To rapidly predict the very short-term (2-day to 7-day) risk of completing a major ischemic stroke
Do Not Use If
Patient has an ongoing, non-resolving neurologic deficit (they are having a stroke, not a TIA, and require acute stroke protocol).
Section 2
Formula & Logic
Scoring Logic
The highest points (2 points each) are heavily weighted toward established, robust markers of true ischemia: unilateral physical weakness, and long-lasting discrete events (≥60 minutes). Lesser symptoms like isolated speech difficulty or short events get 1 or 0 points.
Modern neurology guidelines (e.g., AHA/ASA) have largely moved away from pure time-based criteria in favor of tissue-based criteria (presence of acute infarction on MRI DWI). While the ABCD2 score is helpful for initial ED triage, a low score does NOT safely rule out true cerebrovascular danger if carotid stenosis or atrial fibrillation is the underlying cause.
ABCD³-I Expansion
Recent iterations have added points for dual TIAs, ipsilateral high-grade carotid stenosis, and abnormal DWI on MRI (the ABCD³-I score), which vastly improves predictive accuracy over the original ABCD2 score alone.
Section 4
Evidence Appraisal
Original Derivation
Validation and refinement of scores to predict very early stroke risk after transient ischaemic attack.
Johnston SC et al. • Lancet.. 2007;369(9558):283-92. Combined the previous ABCD and California scores to create a unified ABCD2 index using independent cohorts comprising >4700 patients.
