Driving performance in persons with mild to moderate symptoms of multiple sclerosis

Purpose: To investigate whether driving performance is impaired in persons with mild to moderate multiple sclerosis (MS). Method: This study included 15 persons with MS (pwMS) and 17 healthy controls. The MS group exhibited mild to moderate impairments on the Expanded Disability Status Scale (median, Q1–Q3; 3.5, 2.5–4). The driving simulation required participants to drive in daily traffic while attending to a divided attention (DA) task. Computerized measures on the driving task included number of accidents, tickets, speed maintenance, standard deviation of lateral position, and time to collision. Response times and accuracy on the DA task were also computer generated. Additionally, pwMS completed a clinical evaluation encompassing motor, functional, visual, psychosocial and cognitive tests. Results: No differences between healthy controls and pwMS were observed on all measures of the primary driving task. PwMS performed worse than healthy controls on DA response time (3.10 s, 2.87–3.68 versus 2.15 s, 2.04–2.43; p = 0.001) and accuracy (15 correct answers, 11–18 versus 24 correct answers, 22–25; p < 0.0001). Depression was significantly associated with time to collision (r = −0.77; p < 0.01). Conclusions: Subjects with mild to moderate MS are able to prioritize the driving task above the DA task. The relationship between depression and driving performance in MS merits further investigation. Implications for Rehabilitation Divided attention (DA) is one of the key determinants of safe driving. Driving-related DA is deteriorated in early MS, but does not affect driving performance. Drivers with MS should be advised to avoid unnecessary distraction while driving.