Application of the ABCD2 score to identify cerebrovascular causes of dizziness in the emergency department.

BACKGROUND AND PURPOSE Dizziness can herald a cerebrovascular event. The ABCD(2) score predicts the risk of stroke after transient ischemic attack partly by distinguishing transient ischemic attack from mimics. We evaluated whether this score would also identify cerebrovascular events among emergency department patients with dizziness. METHODS We retrospectively identified consecutive adults presenting to a university emergency department with a primary symptom of dizziness, vertigo, or imbalance. Two neurologists independently reviewed medical records to determine whether the presenting symptom was caused by a cerebrovascular event (ischemic stroke, transient ischemic attack, or intracranial hemorrhage). ABCD(2) scores were then assigned using clinical information from the medical record. The ability of the score to discriminate between patients with cerebrovascular events and those with other diagnoses was quantified using the c statistic. RESULTS Among 907 dizzy patients (mean age, 59 years; 58% female), 37 (4.1%) had a cerebrovascular cause, the majority of which were ischemic strokes (n=24). The median ABCD(2) score was 3 (interquartile range, 3-4). The ABCD(2) score predicted ultimate diagnosis of a cerebrovascular event (c statistic, 0.79; 95% CI, 0.73-0.85). Only 5 of 512 (1.0%) patients with a score of ≤ 3 had a cerebrovascular event compared to 25 of 369 patients (6.8%) with a score of 4 or 5 and 7 of 26 patients (27.0%) with a score of 6 or 7. CONCLUSIONS The ABCD(2) score may provide useful information on dizzy emergency department patients at low-risk for having a cerebrovascular diagnosis and may aid frontline providers in acute management if validated prospectively.