Daytime somnolence in adult sleepwalkers

Abstract Objectives Sleepwalkers often complain of excessive daytime somnolence (EDS). Our retrospective study aimed to document the presence of EDS in a substantial sample of sleepwalkers and to explore the contribution of other sleep disorders, nocturnal sleep disruption, and sleep depth to the alteration of their daytime vigilance. Methods Seventy adult sleepwalkers and 70 control subjects completed the Epworth Sleepiness Scale (ESS). Sleepwalkers also were studied for one night in the sleep laboratory. We compared the sleep profiles of 32 somnolent vs 38 nonsomnolent sleepwalkers and investigated the relationship between ESS scores and sleep-related variables. Results No differences were found in polysomnographic (PSG) parameters. Slow-wave activity (SWA) also was similar in the two subgroups. Sleepwalkers’ ESS scores were not correlated with their body mass index (BMI) or periodic limb movements during sleep (PLMS) index, but they tended to be negatively correlated with indices of respiratory events. Conclusions The EDS reported by adult sleepwalkers does not appear to be explained by the presence of concomitant sleep disorders or PSG signs of nocturnal sleep disruption. These results raise the possibility that EDS is part of the sleepwalking phenotype and that it is linked to its underlying pathophysiology.