Sleep disorders in multiple sclerosis in China: clinical, polysomnography study, and review of the literature.

Sleep disorders are common in multiple sclerosis (MS). The aim of this study was to assess the subjective and objective sleep disturbances in patients with MS and to investigate their relationships with fatigue and excessive daytime sleepiness. All participants completed standardized questionnaires and underwent nocturnal polysomnography. English literature regarding MS and sleep disorders was systematically reviewed through PubMed searches. Eleven patients with MS with fatigue, 10 patients with MS without fatigue, and 11 controls were included in the study. According to the Pittsburg sleep quality index, 61.9% of the patients with MS were poor sleepers and based on the Epworth sleepiness scale, 38.1% of the patients with MS met the criteria of excessive daytime sleepiness. Additionally, patients with MS had more disturbed sleep with higher total arousal index (P < 0.01) and periodic limb movement arousal index (P < 0.001) than controls. None of the patients or controls had an apnea/hypopnea index greater than five. One patient had restless legs syndrome and four had rapid eye movement sleep behavior disorder. Our study shows that sleep disorders and excessive daytime sleepiness are frequent in MS.