Effect of Rapid Eye Movement Sleep Behavior Disorder on Obstructive Sleep Apnea Severity and Cognition of Parkinson's Disease Patients

Abstract

Background:Rapid eye movement (REM) sleep behavior disorder (RBD) and obstructive sleep apnea (OSA) are the most common sleep disorders in Parkinson's disease (PD). The aim of this study was to identify whether RBD could alleviate OSA severity in PD patients and its effect on cognitive impairment.Methods:From February 2014 to May 2017, we recruited 174 PD patients from the Second Affiliated Hospital of Soochow University, all of whom underwent polysomnography (PSG). We collected clinical data, PSG results, and compared information between patients with and without RBD or OSA by analysis of covariance. We also investigated the effect of these sleep disorders on cognitive impairment using linear regression.Results:We grouped participants as follows: PD only (n = 53), PD + OSA (n = 29), PD + RBD (n = 61), and PD + RBD + OSA (n = 31). Minimum oxygen saturation (SaO2) during whole sleep and in REM sleep was higher in PD + RBD + OSA patients than that in PD + OSA patients. PD + RBD patients had worse Mini-Mental Status Examination and Montreal Cognitive Assessment (MoCA) scores than those in the PD group (P < 0.001), especially in visuospatial/executive, attention, and memory functions. The PD + OSA group performed worse than the PD group in the delayed recall domain. After adjusting for age, sex, body mass index, education, disease severity, and other sleep disorders, MoCA was negatively associated with OSA (β = −0.736, P = 0.043) and RBD (β = −2.575,P < 0.001). The severity of RBD (tonic/phasic electromyography activity) and OSA (apnea-hypopnea index/oxygen desaturation index/minimum SaO2) were also associated with MoCA. The adjusted β values of RBD-related parameters were higher than that for OSA.Conclusions:We found that RBD alleviated OSA severity; however, RBD and OSA together exacerbated PD cognitive impairment. Further studies are needed to evaluate whether OSA treatment can improve cognition in PD.

Respiratory dysfunction in Parkinson's disease: a narrative review

“…Surprisingly, the authors found that patients with abnormal persistence of chin muscle tone still presented obstructive apnoea during REM sleep, and similar findings were described by HUANG et al [46]. It may be reasonable that there is a correlation between motor disability and apnoea, as suggested in some studies [42,44], but the role of PD medications is not clear, and it has to be specified that in these studies, motor disability and apnoea were assessed in the "on" state, so the real contribution of dopaminergic drugs could not be clearly assessed.…”

Obstructive Sleep Apnea in Neurodegenerative Disorders: Current Evidence in Support of Benefit from Sleep Apnea Treatment

“…This is supported by one study showing that 63% of patients with PD and RBD had mild cognitive impairment (MCI) as opposed to 33% with isolated PD and 33% with idiopathic RBD [183]. Furthermore, studies suggest that RBD and OSA together can act synergistically to increase cognitive dysfunction in PD [37,175]. Interestingly, our group found that OSA treatment with CPAP improved RBD symptoms in a cohort of mostly early stage PD patients [185].…”

“…However, evidence is discordant. One study found that patients with the combination of PD, OSA, and RBD had a higher nadir oxygen saturation throughout the whole night and during REM sleep [37]. This is supported by other studies which have also observed a lower apnea-hypopnea index in patients with RBD [174,175].…”

“…A study conducted by our group found that cognitive dysfunction, measured using the Montreal Cognitive Assessment (MoCA), was greater in PD patients with concomitant OSA as compared with PD patients without OSA and that the impairment increased with OSA severity [36]. Other groups that looked at global cognitive function measures have found similar results [37][38][39]. Specific domain most often affected were attention and vigilance, visuospatial abilities, and executive function [39].…”

“…Motor manifestations in PD with RBD seem to differ from PD without RBD, exhibiting a non-tremor predominant phenotype and perhaps more postural instability and falls [168,[176][177][178][179][180]. In most studies, a combination of RBD and PD is associated with more excessive daytime sleepiness, worse performance on neurocognitive screening tests (MMSE and MOCA), and impairments in specific neurocognitive domains, especially attention and vigilance, executive functions, and memory impairments [37,[181][182][183][184]. This is supported by one study showing that 63% of patients with PD and RBD had mild cognitive impairment (MCI) as opposed to 33% with isolated PD and 33% with idiopathic RBD [183].…”