Polysomnographic and clinical features in narcoleptic patients with rapid eye movement sleep behaviour disorder

Abstract

Objective To describe clinical features, polysomnographic (PSG) alterations and characteristics of motor and distribution during rapid eye movement (REM) sleep in narcoleptic patients with REM sleep behavior disorder (RBD). Methods We retrospectively summarized general features of 22 narcoleptic patients with RBD, 96 narcoleptic patients without RBD and 21 healthy subjects as controls. We compared their PSG and the related indexes in 3 groups. Then we analyzed a full-night video-PSG recording in a continuous series in 22 narcoleptic patients with RBD to identify their motor behavior and distribution features. Results There was no significant difference in PSG parameter and correlation index between the narcoleptic patients with RBD group and without RBD group. However, compared with normal control group（20.15±4.52）, narcoleptic patients with or without RBD（24.07±5.44，23.40±4.50）showed increased the body mass index(F=4.869，P=0.009) ,shortened NREM sleep and REM sleep (min) latency at night(4.41±7.01, 3.55±3.98 and 14.69±9.62， χ2=31.697，P=0.000；69.39±81.39, 71.04±74.45 and 115.31±45.13， χ2=11.485，P=0.003), increased percentage of sleep stage 1, decreased percentage of slow wave sleep, delayed the arousal time and increased number of arousal episode longer than 5 minutes. In narcoleptic patients with RBD, RBD episodes occurred frequentlyatany stage of REM sleep through whole night and the frequency of vocalizations did not significantly differ between the two halves of the night. Pantomimes were significantly more frequent in RBD episodes of the second half of the night. Conclusions The prevalence of RBD is high in narcoleptic patients. Sleep architecture doesn’t differ between narcoleptic patients with and without RBD. There is no correlation between the occurrence of RBD and narcoleptic duration. In narcoleptic patients with RBD, vocalizations and pantomimes accounted formajor proportion of RBD episodes while aggressive-violent movements are rare. Key words: Narcolepsy; REM sleep behavior disorder; Polysomnography