Diagnostic thresholds for quantitative REM sleep muscle densities, phasic burst duration, and REM atonia index in REM sleep behavior disorder with co-morbid obstructive sleep apnea

Abstract

Introduction Previous REM sleep without atonia (RSWA) studies have excluded patients with sleep apnea, potentially limiting application to clinical REM sleep behavior disorder (RBD) populations. We determined whether phasic burst duration and conventional RSWA methods could accurately diagnose RBD patients with co-morbid OSA. Materials and methods We analyzed RSWA phasic burst durations, phasic, “any” and tonic densities, and automated REM atonia index (RAI) in RBD and matched controls with OSA. Group RSWA metrics were then analyzed and regression models fit to explore associations with clinical variables, with receiver operator characteristic (ROC) curves determining the best diagnostic cut-off thresholds for RBD diagnosis. Results All mean RSWA phasic durations and densities were higher in RBD patients than controls ( p p Conclusion This study provides evidence for RSWA diagnostic thresholds applicable in clinical RBD patient populations with co-morbid OSA using conventional EMG lead placements during split-night polysomnograms, with suggested cut-offs for combined SM/AT muscles of 43.4%, RAI of 0.88, and phasic muscle burst durations of 0.65 and 0.79 s in the SM and AT muscles, respectively. Future studies with similar methods in idiopathic RBD patients with co-morbid OSA are planned. Acknowledgements The project described was supported by a Mayo Clinic Alzheimer’s Disease Research Center Grant Award from the National Institute on Aging (P50 AG016574), and the National Center for Research Resources and the National Center for Advancing Translational Sciences, National Institutes of Health, through Grant No. 1 UL1 RR024150-01. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.