Hazard Perception Skill and Driver Behavior in Patients With Functional Neurologic Disorders

Background and Objectives Driving in patients with functional neurologic disorders (FND) is a major concern, but current guidelines (where they exist) are based on expert consensus only due to a lack of relevant empirical evidence. This study aimed to provide such evidence by comparing drivers with FND with healthy controls on aspects of driving performance and behavior important to crash risk, including hazard perception skill.

Methods Participants completed validated self-report questionnaires of driving behaviors (assessing lapses, errors, violations, and attentional issues) and 2 computer-based measures of hazard perception skill (both known to be associated with crash risk).

Results We compared 43 patients who experience dissociative attacks or functional motor symptoms and 43 healthy controls. Patients with FND self-reported significantly more driving lapses and driving errors compared with healthy controls. However, there were no significant between-group differences in self-reports of ordinary violations, aggressive violations, or attention-related errors. Participants in the FND group and healthy controls exhibited a similar performance on a response time hazard perception test (6.27 vs 5.51 seconds, p = 0.245). However, participants with FND remarkably outperformed the controls in the number of plausible predictions they made in a verbal response hazard prediction test (1.55 vs 1.18 predictions per clip, p = 0.006).

Discussion Our findings suggest that the ability of drivers with FND to predict traffic hazards in between attacks or flares is not worse than that of healthy individuals, with the possibility that it might even be better under some circumstances. Further studies with various populations are needed to replicate our findings.