Characteristics of Objective Sleep and Its Related Risk Factors Among Parkinson's Disease Patients With and Without Restless Legs Syndrome.

Shuyu Sun,Junying Zhou,Changjun Su,Xianchao Zhao,Jinxiang Cheng,Jiafeng Ren

doi:10.3389/fneur.2021.644385

Abstract

Objective: This study aimed to investigate the objective sleep characteristics and their related risk factors among Parkinson's disease (PD) patients with and without restless legs syndrome (RLS).Methods: A total of 125 patients with PD who underwent overnight polysomnography (PSG) were recruited consecutively. Eighty-one patients, including 27 PD with RLS (PD-RLS) and 54 PD without RLS (PD-NRLS), were included in the final analysis after 1:2 propensity score matching. Demographic, clinical, and polysomnographic data were compared between PD patients with and without RLS. The risk factors for sleep quality were examined using a multiple linear regression model.Results: The prevalence of RLS among PD patients was 28.0% (35/125). The PD-RLS group exhibited a higher score for the Unified Parkinson Disease Rating Scale (UPDRS) III than the PD-NRLS group. Also, the PD-RLS patients displayed significantly shorter total sleep times, worse sleep quality, decreased stage 3 duration, a longer wake time after sleep onset, and a higher arousal index than those without RLS (all p < 0.05). In the multiple linear regression model, PD duration (β = −0.363, 95% CI: −0.652 to −0.074; p = 0.016), UPDRS-III (β = −0.356, 95% CI: −0.641 to −0.071; p = 0.016), and periodic limb movement index (PLMI) (β = −0.472, 95% CI: −0.757 to −0.187; p = 0.002) were determined to be the risk factors influencing sleep quality in PD-RLS patients. The UPDRS-III (β = −0.347, 95% CI: −0.590 to −0.104; p = 0.006) and HAMD scores (β = −0.343, 95% CI: −0.586 to −0.100; p = 0.007) were significantly associated with sleep quality after adjusting for confounding factors in PD-NRLS patients, respectively.Conclusions: PD-RLS patients exhibited more disturbed and fragmented sleep in objective sleep architecture than PD-NRLS patients. The severity of motor symptoms in PD was significantly associated with poor sleep quality in both PD-RLS and PD-NRLS patients. Notably, our findings indicated that periodic limb movements during sleep (PLMS) was the risk factor that influenced the objective sleep quality in PD patients with RLS.

Highlights

Parkinson’s disease (PD) is the second most common neurodegenerative disease among people older than 65 years old in China [1]
There were no significant differences in age at the time of restless legs syndrome (RLS) diagnosis, sex, body mass index (BMI), age at onset of PD, and duration of PD between the groups
No differences were observed in the motor phenotype of PD, H-Y stage, levodopa equivalent dose (LED), HAMD scores, and Epworth Sleepiness Scale (ESS) between PD patients with or without RLS

Summary

Introduction

Parkinson’s disease (PD) is the second most common neurodegenerative disease among people older than 65 years old in China [1]. It is a movement disorder characterized by motor symptoms such as a resting tremor, rigidity, bradykinesia, and postural instability. Sleep disturbances appear to be the most frequent non-motor symptoms, as they are observed in up to 90% of PD patients [3, 4]. The categories of sleep disturbances in patients with PD comprise insomnia, daytime sleepiness, restless legs syndrome (RLS), rapid eye movement sleep behavior disorder (RBD), and so on. The regulation of sleep and wakefulness is affected by the dysfunction of multiple brain areas and neurotransmitters in patients with PD [5]

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Discussion

Conclusion