ABCD² Score (TIA Risk): Explanation and Clinical Context The ABCD² Score is a validated clinical tool designed to estimate the short-term risk of stroke following a Transient Ischemic Attack (TIA). It was developed by Rothwell et al. and published in Lancet (2005), combining simple clinical features—Age, Blood Pressure, Clinical presentation, Duration, and Diabetes—to predict stroke risk within 2, 7, and 90 days after a TIA.
Each component contributes a weighted score based on its relative predictive power. Age >60 years and elevated blood pressure (>140/90 mmHg) represent vascular risk burden. Clinical presentation, especially unilateral weakness or speech disturbance, strongly correlates with early stroke occurrence. Longer duration of symptoms indicates a greater ischemic burden, while diabetes further increases cerebrovascular vulnerability.
Patients with a total score <3 are considered low-risk and may be managed in an outpatient setting if prompt evaluation is available. Those with scores >4 are at moderate to high risk and warrant hospital observation and urgent etiologic workup (e.g., neuroimaging, carotid studies, and cardiac evaluation).
Although the ABCD² score offers a rapid triage tool, it does not replace imaging-based or etiologic assessments. Subsequent refinements, such as the ABCD³-I Score, incorporate recurrent TIA episodes and MRI diffusion abnormalities, improving predictive accuracy for early stroke.
Reference:
Rothwell PM, Giles MF, Flossmann E, et al. A simple score (ABCD) to identify individuals at high early risk of stroke after transient ischaemic attack. Lancet. 2005;366(9479):29–36.
Johnston SC, Rothwell PM, Nguyen-Huynh MN, et al. Validation and refinement of scores to predict very early stroke risk after transient ischaemic attack. Lancet Neurology. 2007;6(10): 871–880.