Driving after concussion: Is it safe to drive after symptoms resolve?

Post-concussion impairments may result in unsafe driving performance, but little research is available to guide consensus on when concussed individuals should return to driving. The purpose of this study was to compare driving performance between individuals with and without a concussion and to explore relationships between neuropsychological and driving performance. Fourteen participants with concussion (age 20.2 ± 0.9 years old) and 14 non-concussed age- and driving experience-matched controls (age 20.4 ± 1.1 years old) completed a graded symptom checklist, a brief neuropsychological exam, and a 20.5 km driving simulation task. Participants with a concussion completed driving simulation within 48 h of becoming asymptomatic (15.9 ± 9.0 days post-concussion). One-way analyses of variance were used to compare total number of crashes, tickets, and lane excursions, as well as standard deviation of lateral position (SDLP) and standard deviation of speed. Pearson's correlations were conducted to explore the relationship between the neuropsychological and driving performance separately by group (α = 0.05). Participants with a concussion committed more frequent lane excursions (concussed 10.9 ± 4.5; controls 7.4 ± 2.4; p = 0.017) and exhibited greater SDLP, compared with controls, during the first curve (concussed 45.7 ± 21.3 cm, controls 27.4 ± 6.1 cm; p = 0.030) and final curve (concussed 39.6 ± 24.4 cm; controls 33.5 ± 21.3 cm; p = 0.036). Poorer performance on symbol digit modalities (r = -0.54), Rey Osterrieth Complex Figure (r = -0.53), verbal memory (r = -0.77), and motor speed (r = -0.54) were correlated with more frequent lane excursions in the concussed group, but not in the control group. Despite being asymptomatic, concussed participants exhibited poorer vehicle control, especially when navigating curves. Driving impairments may persist beyond when individuals with a concussion have returned to driving. Our study provides preliminary guidance regarding which neuropsychological functions may best indicate driving impairment following concussion.