Study on objective sleep disturbances in patients with Parkinson’s disease

Abstract

Objective To investigate the characteristics of the objective sleep disturbances in Parkinson’s disease (PD) and the factors related to it. Methods One hundred and one PD patients and 90 age- and sex- matched controls underwent a video-polysomnography. The sleep parameters and its related factors in two groups were analyzed. Results Sleep latency was not statistically different in comparing two groups. PD patients had a higher percentage of non-rapid eye movement（non-REM）sleep stage 1 and a lower percentage of non-REM sleep stage 2 compared with controls（27.9±17.8 vs 21.2±11.7，t=3.034, P=0.003；47.8±17.4 vs 54.7±12.9，t=-3.043, P=0.003）. Reduced sleep efficiency, decreased the proportion of slow wave sleep and REM sleep, increased awake time and longer REM sleep latency occurred in PD patients. There were no significant differences of these above parameters. Some sleep parameters in PD patients were correlated with advancing age, the severity of PD, and the degree of depression. The index of periodic leg movements in sleep (PLMSI) of 41 PD patients (40.6%) was more than 15. These PD patients didn’t complain corresponding symptoms about their legs. The PLMSI in PD patients were significantly higher than the controls. PLMSI increased with aging in the PD group(r=0.261，P<0.01). PD patients didn’t suffer significantly lower apnea- hypopnea index and oxygen desaturation index. The lowest SPO2(L-SPO2)increased in the PD group. REM sleep without atonia occurred in 83 patients (82.2%)with PD．Thirty-eight patients (37.6%) were diagnosed with REM sleep behavior disorder (RBD). The incidences of REM without atonia and RBD in the PD group were significantly higher than in the controls（0 and 8 patients (8.9%), χ2=42.271，102.480; both P<0.01). Conclusions The sleep parameters in PD patients are changed．For PD patients, there is no difficulty in falling asleep. The PD patients also have sleep structure disorder and difficulty in maintaining sleep. The sleep parameters are correlated with advancing age, the severity of PD, and the degree of depression in PD. PLMS don’t lead to sleep disturbances in PD patients. The blood oxygen saturation don’t decrease severely when PD patients suffer apnea or hypopnea. RBD occur more frequently in PD patients.