A Comparison Of Clinical, Motor, Cognitive, And Driving Performance Among Young Adults Following MTBI

Adolescents and young adults are the highest-risk drivers in the United States. As mild traumatic brain injury (mTBI) impacts millions of young adults, it is paramount to understand whether residual motor and cognitive deficits may exacerbate risk among young drivers. With the anticipated increase in conditionally automated vehicles (CAV) on the road, it is further necessary to understand the ability of young drivers with mTBI to appropriately negotiate takeover transitions to ensure the safety of oneself and bystanders. PURPOSE: To quantify clinical, motor, cognitive, and driving takeover performance in a CAV for up to one month among mTBI and healthy drivers. METHODS: Young adults aged 16-35 are evaluated within seven, 14, and 30 days of mTBI diagnosis. Age- and gender-matched healthy controls are evaluated at similar time periods. Clinical assessments, as performed by sports medicine physicians include vestibular-ocular motor screening and the SCAT 6. Motor tests include standing balance during the sensory organization test as well as single- and dual-task gait performance. During dual-task conditions, participants are asked to walk while performing a verbal fluency task. Driving performance is assessed in an autonomous driving simulator, with takeover timeliness and quality quantified along with cognitive measures of situational awareness, subject workload, and eye tracking. Differences in performance across groups and visits are assessed using two-way mixed effects ANOVAs. RESULTS: Preliminary results indicate greater gait velocity reductions (0.37 m/s vs 0.24 m/s) during dual-task conditions among mTBI compared to healthy young adults. Along with slower verbal reaction times, participants with mTBI further demonstrated lower success rates (71% vs 90%) and greater pupil dilation (5.3 mm vs 4.8 mm) during takeover tasks in the CAV environment (p < 0.001). CONCLUSION: The use of a multimodal assessment battery allows for a more comprehensive assessment of individuals with mTBI, providing potential evidence of residual deficit and the need for improved metrics to inform return to driving decision-making.