Electromyography activity level in rapid eye movement sleep predicts neurodegenerative diseases in idiopathic rapid eye movement sleep behavior disorder: a 5-year longitudinal study

Yaping Liu; Jihui Zhang; Siu Ping Lam; Mandy Wai Man Yu; Shirley Xin Li; Junying Zhou; Ngan Yin Chan; Jing Wang; Hongliang Feng; Anne Chan; Vincent Mok; Yun Kwok Wing

doi:10.1016/j.sleep.2019.01.018

Electromyography activity level in rapid eye movement sleep predicts neurodegenerative diseases in idiopathic rapid eye movement sleep behavior disorder: a 5-year longitudinal study

Sleep Med. 2019 Apr:56:128-134. doi: 10.1016/j.sleep.2019.01.018. Epub 2019 Jan 28.

Authors

Affiliations

¹ Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
² Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China. Electronic address: jihui.zhang@cuhk.edu.hk.
³ Department of Psychology, The University of Hong Kong, Pokfulam, Hong Kong, China; The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China.
⁴ Sleep Medicine Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
⁵ Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; Department of Psychology, The University of Hong Kong, Pokfulam, Hong Kong, China.
⁶ Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, China.

PMID: 30852128
DOI: 10.1016/j.sleep.2019.01.018

Abstract

Objectives: To investigate whether baseline electromyography (EMG) activity during rapid eye movement (REM) sleep predicts the development of neurodegenerative diseases over time in patients with idiopathic REM sleep behavior disorder (iRBD).

Methods: A total of 216 patients with polysomnography-confirmed iRBD were recruited from September 1997 to December 2016 with a mean follow-up duration of 5.0 ± 3.7 years (median: 4.0, range: 0.5-19.0). Neurodegenerative diseases were ascertained according to standard diagnostic criteria during follow-up. Time-dependent receiver operating characteristic (ROC) curves were employed to evaluate the dynamic predictive performance of EMG activity over time. Both tonic and phasic EMG activity were dichotomized into 'mild' and 'severe' categories by the ROC curves estimated optimal cut-offs.

Results: A total of 58 patients (26.9%) developed neurodegenerative diseases. The predictive performance of tonic EMG activity was stable (area under the curve of approximately 0.68) over time, while the performance of phasic EMG activity was significantly superior to chance only after five years of follow-up. The optimal cut-off for prediction at five years was 15.4% (sensitivity, 0.69; specificity, 0.57) and 7.8% (sensitivity, 0.79; specificity, 0.47) for tonic and phasic EMG activity, respectively. Cox proportional hazards regression analyses further revealed that severe tonic (adjusted HR: 2.76, 95% CI: 1.35-5.62) and phasic EMG activity (adjusted HR: 3.10, 95% CI: 1.10-8.71) were associated with early development of Parkinson's disease (PD) and dementia with Lewy bodies (DLB), respectively.

Conclusions: Tonic but not phasic EMG activity may serve as a stable biomarkers for predicting the progression of neurodegeneration in iRBD.

Keywords: Neurodegenerative diseases; REM sleep behavior disorder; REM sleep without atonia; Time-dependent receiver operating characteristic.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aged
Biomarkers
Electromyography*
Female
Humans
Longitudinal Studies
Male
Middle Aged
Neurodegenerative Diseases / diagnosis*
Parkinson Disease / diagnosis
Prognosis
REM Sleep Behavior Disorder / diagnosis*
Sleep, REM*

Substances

Biomarkers