THURSDAY, Nov. 20, 2025 (HealthDay News) -- The risk for motor vehicle crashes is increased after a concussion, according to a study published online Nov. 5 in BMJ Open.Donald A. Redelmeier, M.D., from Sunnybrook Research Institute in Toronto, and colleagues examined whether past concussion is associated with the risk for a subsequent serious motor vehicle crash in a population-based longitudinal cohort analysis. A total of 3,037,028 patients were identified from April 1, 2002, to March 31, 2022, from 178 emergency departments, including 425,158 with a concussion (cases) and 2,611,870 with an ankle sprain (controls).The researchers found that during a median follow-up of 10 years, 200,603 patients were injured in a subsequent motor vehicle crash, equivalent to an absolute risk of one in 15 patients (6.64 per 1,000 patient-years). Compared with those with ankle sprain, patients with a concussion had a significantly elevated motor vehicle crash risk (adjusted relative risk, 1.49). In the early weeks after a concussion, the increased risk was particularly high, and it remained independent of other risk factors, applied to diverse clinical groups, and was accentuated after repeat concussions. The risk extended across crash severity, was higher for single-vehicle events, and was replicated after adjustment for confounding."The risk of a motor vehicle crash after a concussion suggests current mitigating efforts are insufficient; however, driving cessation may be unreasonable since the risk also extends to patients as pedestrians," the authors write. "Instead, clinicians might warn concussion patients to be cautious about prevailing motor vehicle crash risks along with standard anticoncussion campaigns."Abstract/Full Text.Sign up for our weekly HealthDay newsletter