Outcomes Among Patients Discharged From the Emergency Department With a Diagnosis of Peripheral Vertigo

Objective: We aimed to determine the risk of short-and long-term stroke, as well as accidental injury, in patients discharged from an emergency department who were given a diagnosis of a peripheral vestibular disorder. Methods: In this population-based, retrospective, cohort study, we identified all adult patients who were discharged from an emergency department in Ontario, Canada, between 2006 and 2011, with a primary diagnosis of a peripheral vestibular disorder. We assessed hospitalized strokes at 7, 30, 90, and 365 days, as well as subsequent falls, motor vehicle accidents, fractures, and burns. To provide context, we assessed the same outcomes in propensity score-matched discharged emergency department patients with renal colic. Results: Among 41,794 qualifying patients, 76 (0.18%) had a stroke within 30 days. Accidental injury at 30 days ranged from 0.01% (falls) to 0.15% (fractures). The relative risk (RR) of 30-day stroke was 9.3 (95% confidence interval [CI]: 4.3-20.3) times higher than among matched renal colic controls. The RR was highest at 7 days (50.0; 95% CI, 6.9-362.0) and diminished with duration from the emergency department visit: RR 6.1 (95% CI, 3.5-10.7) at 90 days and 2.5 (95% CI, 1.8-3.5) at 1 year. There was no difference in the risk of accidental injury. Interpretation: The frequency of early stroke after discharge from an emergency department with a diagnosis of a peripheral vestibular disorder was extremely low. However, the relative risk was markedly higher than in matched patients with renal colic, suggesting that some strokes, or sentinel events for strokes, are being misdiagnosed as peripheral vestibular disorders.