0682 A Novel, Highly Efficient REM Sleep without Atonia Visual Analysis Method for REM Sleep Behavior Disorder Diagnosis

Abstract

Polysomnographic REM sleep without atonia (RSWA) is requisite for REM sleep behavior disorder (RBD) diagnosis, yet traditional scoring criteria for phasic muscle bursts (requiring minimum duration of 100ms) are tedious and labor intensive, and overlap with state-independent excessive fragmentary myoclonus. Furthermore, traditional quantitative RSWA metrics have created confusion and further limited adaption of RSWA quantification by sleep clinicians. We aimed to simplify phasic RSWA scoring criteria and derived RSWA metrics to expedite RSWA analysis while maintaining high diagnostic precision. Fifteen iRBD patients and 30 OSA controls who have been previously reported underwent manual RSWA analysis utilizing a 1 second minimum phasic muscle duration cutoff (maximum 14.9 seconds). RSWA was analyzed in the submentalis (SM) and anterior tibialis (AT) muscles. The total duration of REM sleep with phasic muscle activity was divided by total non-artifact REM time, yielding a “density of muscle activity” during REM sleep. Parametric mean comparison and receiver operating characteristic (ROC) curves were used to determine the best diagnostic cutoff thresholds for RBD and compared with previously published cutoffs from this cohort. Mean RSWA densities were significantly higher in RBD patients vs. OSA controls, for both SM (11% vs. 0.4%, p<0.01) and AT (10% vs. 1.3%, p<0.01), with best diagnostic cut-offs for SM of 4.0% (AUC = 0.92) and AT of 4.3% (AUC = 0.94), which were highly similar to previously determined diagnostic discrimination using shorter phasic burst duration scoring criteria. Increasing minimum phasic duration criteria to 1 second, with calculation of a unitary RSWA metric greatly simplifies and expedites manual RSWA analysis without sacrificing diagnostic sensitivity and specificity, yielding an approach to RSWA analysis that is both more intuitive and easily employed in busy clinical sleep laboratory settings. Support (If Any):