Examination of simulated driving performance throughout concussion recovery

Research Objectives: To determine whether simulated driving performance improves as days since concussion increase.

Design: Cross-sectional

Setting: Clinical research laboratory

Participants: 49 patients with concussion (age:19.3±1.5 years, 61.2% female, N=25 general university students, N=24 collegiate athletes).

Interventions: Not applicable

Main Outcome Measures: Participants completed a 6-mile driving simulation assessment at their first clinical visit (range:1-12 days) with the following segments: overtaking on a highway, traffic light, highway left curve, highway right curve, child pedestrian crossing, crosswalk, residential right curve, residential left curve, incurring vehicle in the lane, navigating to the left of a car crash in the right lane, and a vehicle following task. Full drive outcomes included number of collisions, speed exceedances, stop signs missed, centerline crossings, road-edge excursions, total drive time, percent time over the speed limit, and percent time out of lane. We extracted average speed, standard deviation of speed (SDS), lateral lane position, and standard deviation of lateral lane position (SDLP) for each segment. We used Spearman’s rho correlations to determine whether days since concussion was related to each drive outcome.

Results: Fewer days since concussion was associated with greater centerline crossings (rho=-0.36,p=0.011), percent time out of lane (rho=-0.36,p=0.010), and SDLP while navigating: highway left curve (rho=-0.29,p=0.043), crosswalk (rho=-0.58,p < 0.001), and around a car crash (rho=-0.32,p=0.025). Fewer days since concussion was associated with a lateral lane position shifted toward the centerline while navigating: residential left curve (rho=0.51,p < 0.001), incurring vehicle in the lane (rho=0.41,p=0.004), and around a car crash (rho=0.32,p=0.027).

Conclusions: Patients had poorer lateral vehicle control and drove closer to/crossed the centerline more frequently in the earlier days after injury, which are driving behaviors related to crash risk. More research is needed to determine when driving performance recovers post-concussion.

Author(s) Disclosures: This research was partially supported by the Andee's Army Foundation and by the National Center for Advancing Translational Sciences of The National Institutes of Health (UL1TR002378). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.