Objective daytime sleepiness in patients with somnambulism or sleep terrors

To objectively measure daytime sleepiness and to assess for clinical and polysomnographic determinants of mean sleep latency in adult patients with somnambulism (sleepwalking [SW]) or sleep terrors (ST) compared with controls.

Thirty drug-free adult patients with primary SW or ST, and age-, sex-, and body mass index-matched healthy controls underwent a standardized clinical interview, completed questionnaires including the Epworth Sleepiness Scale, and underwent one night of video polysomnography followed by the Multiple Sleep Latency Test (MSLT).

Excessive daytime sleepiness defined as Epworth Sleepiness Scale score >10 was reported in 66.7% of patients and 6.7% of controls. The temporal pattern of sleep latencies in individual MSLT trials differed between patients and controls, with progressive increased sleep latency in patients across the trials in contrast to a "U curve" for controls. We did not find between-group differences regarding the mean sleep latency on the 5 MSLT trials, but did observe reduced sleep latencies in patients for the first 2 trials. Despite increased slow-wave sleep disruptions found in patients (i.e, more micro-arousals and hypersynchronous high-voltage delta waves arousals), we did not find polysomnographic characteristic differences when comparing sleepy patients for either subjective or objective daytime sleepiness on the MSLT compared with alert patients.

Excessive daytime sleepiness is a common complaint in subjects with SW or ST and shorter sleep latencies in the early morning hours. Despite an increased slow-wave sleep fragmentation found in these patients, we did not identify any association with the level of daytime sleepiness.