Safe driving requires integration of higher-order cognitive and motor functions. Impairment in these functions is common in patients diagnosed with AME, but may improve with appropriate treatment. The time course over which this improvement occurs and its association with driving behaviors are unknown.

Recovering AME patients were recruited from tertiary care clinics at Washington University (Saint Louis, MO). All patients met diagnostic criteria for AME associated with NMDAR (n=2) or LGI1 autoantibodies (n=3). Patients were >21 years-old, had ≥5 years of pre-illness on-road driving experience, and were cleared by their assessing physician to return to driving. Patients consented to installation of a commercial global positioning system data logger—termed the Driving Real World In-Vehicle Evaluation System (DRIVES)—into their private vehicle. Trip data and aggressive actions (e.g., hard braking, sudden acceleration, speeding) were continuously recorded each time the vehicle was driven by the designated driver. DRIVES data were compared between AME patients and a cohort of 2:1 sex-matched cognitively normal individuals enrolled within parallel studies.

Driving behaviors were measured in 5 AME patients (2 females, age range: 28-67 years) beginning with return to driving (median 1.8 months post-diagnosis; range, 0.4-3.8) and continuing for 14 months. When compared to cognitively normal individuals, AME patients were increasingly more likely to take trips ≥10 miles (0.22±0.1 vs. -0.09±0.06 trips per week; p=0.048) and to experience hard braking events (0.2±0.08 vs. -0.01±0.05 events per week; p=0.06) across the follow-up period. No accidents were self-reported by patients or captured by the DRIVES.