Amelioration of Osa in Rem Sleep Behavior Disorder

909 Amelioration of OSA Severity in RBD—Huang et al airway dilator muscle EMG activity at sleep onset15 may cause an individual, who has a more collapsible airway, to develop an obstructive respiratory event. The further reduction of genioglossus activity would explain the increased severity of OSA during normal REM sleep.14 Furthermore, peak and tonic EMG activity in genioglossus has been shown to be associated with stable breathing.14 Strychnine, an antagonist of glycine, has been found to increase upper airway muscles activity with consequent reduction of the duration and oxygen desaturation of apneas in OSA patients.16 As early as the 1990s, Schenck and Mahowald proposed that RBD (related to its REM sleep without atonia [RSWA]) might protect against obstructive sleep apnea.17 Nonetheless, it remains unclear on how excessive EMG activities may modulate the severity of OSA in RBD patients. In this study, we hypothesized that persistence of REM-related EMG activity (REMREEA) could ameliorate the severity of OSA in RBD patients. We aimed to (1) explore the associations of tonic and phasic EMG activities with sleep apnea-related variables in RBD patients; (2) compare the severity of OSA between RBDOSA patients and their OSA controls matched for age, sex, apnea-hypopnea index (AHI) and body mass index (BMI).