Subjective poor sleep quality in Chinese patients with Parkinson's disease without dementia

Parkinson's disease (PD) is a common progressive neurological disorder and is composed of motor and non-motor symptoms. Sleep disturbances are frequent problems for patients with PD. The relationship between sleep disturbances with Hoehn and Yahr (H&Y) staging have been demonstrated. However, the relationship between sleep disorders and H&Y is still unclear in patients with PD without dementia in Chinese PD patients. In this study, we interviewed 487 non-demented PD patients of Chinese Han descents by H&Y classification. We found that night sleep quality was significantly associated with the severity of PD (P = 0.008). Panic disorder severity scale (PDSS) total scores were correlated with PD non-motor symptoms scale (PDNMS) scores (r = -0.528, P < 0.001), the Hamilton depression scale (HAMD) scores (r = -0.545, P < 0.001) and the Hamilton anxiety scale (HAMA) scores (r = -0.498, P < 0.001). Our results indicated that sleep quality deteriorated with the advancing of PD in Chinese non-demented patients with PD. Depression and anxiety may partly explain sleep disturbances in non-demented patients with PD.