Background
Patients with Parkinson’s disease (PD) experience debilitating motor symptoms as well as non-motor symptoms, such as cognitive dysfunction and sleep disorders. This constellation of symptoms has the potential to negatively influence pedestrian safety.
Objective
Investigate the association of motor symptoms, daytime sleepiness, impaired vigilance, and cognitive dysfunction on pedestrian behavior in patients with PD and healthy older adults. Methods: Fifty PD and 25 control participants were evaluated within a virtual reality pedestrian environment and completed assessments of motor performance, daytime sleepiness (Epworth Sleepiness Scale), vigilance (psychomotor vigilance task), and visual processing speed (Useful Field of View: UFOV®) outside of the virtual reality environment. The primary outcome measure was Time to Contact (TTC), defined as the time remaining until a participant would have been hit by an approaching vehicle while crossing the virtual street.
Results
The virtual reality pedestrian environment was feasible in all participants. Patients with PD demonstrated riskier pedestrian behavior compared to controls. Among PD participants, walking speed, objective measures of vigilance, and visual processing speed were correlated with pedestrian behavior, with walking speed being the strongest predictor of Time to Contact, explaining 48% of the variance. Vigilance explained an additional 8% of the variance. In controls, vigilance was also important for street-crossing safety, but older age was the most robust predictor of pedestrian safety.
Conclusion
Walking speed is associated with unsafe pedestrian behavior in patients with PD. In contrast, age was the strongest predictor of pedestrian safety in healthy older adults.