Objective To compare simulated driving performance between concussed and control participants.

Design Cross-sectional.

Setting Laboratory.

Subjects Fourteen concussed participants and 14 non-concussed age and driving experience matched controls with no neurological disorders, medications causing drowsiness, or heavy drugs/alcohol use (Age: 20.3years, 95%CI:19.9,20.7).

Intervention Participants completed a 7.6 minute, 20.5km driving simulation task containing curves, crosswalks, accidents, rural/urban areas, pedestrians, overtaking, and evasion. Concussed participants completed driving simulation within 48 hours of becoming asymptomatic (15.9 days post-concussion, 95%CI: 10.7,21.0) and were deemed clinically recovered by a medical professional using a multifaceted concussion evaluation.

Outcome measures We compared total number of accidents, tickets, and lane excursions between groups.We also comparedaverage velocity (km/hr), standard deviation of velocity, lateral lane position (m), and lateral lane position standard deviation throughout simulation subsections. One-way ANOVAs were used (α=0.05).

Results Concussed participants committed more frequent lane excursions compared to controls (concussed: 10.9, 95%CI:8.3,13.5; controls: 7.4, 95%CI:6.0,8.8; p=0.02). Concussed participants exhibited greater lateral lane position standard deviation compared to controls during the first (concussed: 1.1m, 95%CI: 0.8,1.5; controls: 0.7m, 95%CI:0.6, 0.9; p=0.02) and final curve (concussed: 1.2m, 95%CI:1.1,1.3; controls: 1.0m, 95%CI:0.9,1.1; p=0.04).

Conclusions Despite being considered clinically recovered, concussed participants were less able to centre the vehicle in the lane and entered the shoulder more frequently, especially when navigating curves. A concussion may impair visual, motor, and/or cognitive skills necessary to safely drive. Further research is needed to determine when it is safe to return to driving following concussion.

Competing interests None.