Dissipation of Motor Sleep Inertia and Motor Wake Inertia in Early Relapsing–Remitting Multiple Sclerosis

Abstract

While previous studies have described the time course of the dissipation of motor sleep inertia (around 70 min after wake-up time) and motor wake inertia (around 20 min after bedtime) in healthy controls (HCs), the corresponding knowledge for persons with early relapsing–remitting multiple sclerosis (RRMS) is lacking. To fill in this knowledge gap, we carried out a secondary analysis of previously collected data in 35 persons (24 females; mean age = 31.51 ± 7.74 years) with early relapsing–remitting multiple sclerosis (RRMS) and 35 (24 females; mean age = 31.29 ± 8.02) healthy controls (HCs). Each participant wore an actigraphic Micro Motionlogger Watch (Ambulatory Monitoring, Ardlsey, NY, USA) for seven consecutive days. The Functional Linear Modeling statistical framework was adopted to compare the dissipation of motor sleep inertia as well as motor wake inertia between RRMS and HC. As regards motor sleep inertia, no significant differences in motor activity were observed in the first 70 min after the wake-up time; however, with reference to motor wake inertia, the motor activity of RRMS persons was significantly higher than HCs in approximately the first 30 min after bedtime. Despite the small sample size, this pattern of results suggests that the dissipation of motor wake inertia is only slower in persons with RRMS as opposed to HCs.