Real-time assessment of daytime sleepiness in drivers with multiple sclerosis

Background Daytime sleepiness is a common symptom of multiple sclerosis (MS) that may jeopardize safe driving. The aim of this study was to compare daytime sleepiness, recorded in real-time through eyelid tracking, in a simulated drive between individuals with MS (iwMS) and healthy controls. Methods Fifteen iwMS (age = median (Q1 – Q3), 55 (50 – 55); EDSS = 2.5 (2 – 3.5); 12 (80%) female) were matched for age, sex, education, and cognitive status with 15 controls. All participants completed self-reported fatigue and sleepiness scales including the Modified Fatigue Impact Scale (MFIS), Pittsburg Sleep Quality Inventory (PSQI), and Epworth Sleepiness Scale (ESS). Percentage of eyelid closure (PERCLOS) was extracted from a remote eye tracker while completing a simulated drive of 25 minutes. Results Although iwMS reported more symptoms of fatigue (MFIS, p =0.003) and poorer sleep quality (PSQI, p = 0.008), they did not report more daytime sleepiness (ESS, p = 0.45). Likewise, there were no differences between groups in real-time daytime sleepiness, indexed by PERCLOS (p = 0.82). Both groups exhibited more real-time daytime sleepiness as they progressed through the drive (time effect, p< 0.0001). The interaction effect of group*time (p = 0.05) demonstrated exacerbated symptoms of daytime sleepiness towards the end of the drive in iwMS compared to controls. PERCLOS correlated strongly (Spearman ρ = 0.76, p = 0.001) with distance out of lane in iwMS. Conclusion IwMS show exacerbated symptoms of daytime sleepiness during monotonous, simulate drive. Future studies are warranted to investigate the effect of MS on daytime sleepiness during real-world driving.