Patients with multiple sclerosis (MS) often experience daytime sleepiness, which could have an impact on safe driving. A study used eyelid tracking during a simulated drive to compare daytime sleepiness between patients with MS versus healthy controls.
The study included 15 patients with MS (median age, 55 years; median Expanded Disability Status Scale, 2.5; 12 patients were female) and 15 controls matched by age, sex, education, and cognitive status. Fatigue and sleepiness were self-reported using the Modified Fatigue Impact Scale (MFIS), Pittsburg Sleep Quality Inventory (PSQI), and Epworth Sleepiness Scale (ESS). Patients completed a 25-minute simulated drive, during which time a remote eye tracker was used to record percentage of eyelid closure (PERCLOS).
Patients with MS reported more symptoms of fatigue, per the MFIS (P=0.003), and poorer sleep quality, per the PSQI (P=0.008). However, self-reported daytime sleepiness was not greater in the MS group, per the ESS (P=0.45). Real-time daytime sleepiness, per the PERCLOS, did not largely differ between the groups (P=0.82). In both cohorts, real-time daytime sleepiness increased over the course of the drive (time effect, P<0.0001). In the MS cohort, compared with controls, the interaction effect of group*time presented increased symptoms of daytime sleepiness (P=0.05); a significant correlation was observed between PERCLOS and distance out of lane (P=0.001).
“[Patients with MS] show exacerbated symptoms of daytime sleepiness during a monotonous, simulate drive. Future studies should investigate the effect of MS on daytime sleepiness during real-world driving,” the researchers concluded.