Research Reports - Driving after concussion: Is it safe to drive after symptoms resolve?
J Neurotrauma. 2017 Jan 24. doi: 10.1089/neu.2016.4668. [Epub ahead of print]
Schmidt JD(1), Hoffman NL(1), Ranchet M(2,)(3), Miller LS(4), Tomporowski PD(1),
Akinwuntan AE(5), Devos H(2,)(5).
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.