Sleep disorders in multiple sclerosis in China: clinical, polysomnography study, and review of the literature.
BACKGROUND Patients with multiple sclerosis (MS) report sleep disturbances (SD) and excessive daytime sleepiness (EDS) more frequently than the general population. Our objectives were to evaluate SD and EDS in MS patients and to test the reliability of subjective sleep questionnaires. METHODS Demographic and clinical characteristics of unselected consecutive patients with MS were collected. Different questionnaires were used to assess quality of sleep, daytime sleepiness, fatigue, anxiety, depression and quality of life (QoL). Nocturnal polysomnography and Multiple Sleep Latency Test (MSLT) were performed in 25 selected MS patients with fatigue and with or without EDS. RESULTS 205 MS patients were enrolled. More than half of the MS patients were classified as 'poor sleepers'. In multivariate analysis, SD were correlated with disability, fatigue, depression, QoL, and pain, but not with EDS. Subjective sleepiness evaluated with the Epworth Sleepiness Scale and SD with the Pittsburgh Sleep Quality Index were not correlated with the results of the objective assessments of vigilance (MSLT) and sleep. CONCLUSIONS SD and EDS are frequent among MS patients. Objective assessment of vigilance and sleep can be challenging but MS patients who are poor sleepers should receive immediate assessment and treatment in order to improve QoL.