523 Characteristics of Patients with REM Sleep without Atonia/Periodic Limb Movements of Sleep without Dream Enactment Behaviors

Abstract Introduction While REM sleep without atonia (RSWA) in REM sleep behavior disorder (RBD) is associated with male sex, age greater than or equal to 50 years, alpha-synucleinopathies, and narcolepsy, the characteristics of patients with RSWA/persistent periodic limb movements of sleep in REM sleep (RSWA/PLMS-REM) without dream enactment behaviors are unexplored. The aim of this study was to compare the demographics, comorbidities, and concomitant medication use between RSWA/PLMS-REM patients and non-RSWA/non-PLMS-REM controls. Based on anecdotal clinical observations, we hypothesized that these patients are more commonly young, women, have psychiatric or neurological diseases, and use antidepressants. Methods We conducted a retrospective review of the Mayo Clinic electronic medical record to identify all patients with RSWA/PLMS-REM between November 2018 and November 2020. After excluding all patients with RBD, restless legs syndrome, narcolepsy, and RSWA/non-PLMS-REM, we identified 27 patients. All in-lab polysomnograms (PSGs) were reviewed to calculate the periodic limb movement index per hour of REM sleep (REM-PLMI). We also identified a control group of 15 individuals without RSWA, reviewed their PSGs, and calculated the REM-PLMI. Results The mean REM-PLMI of patients with RSWA was 64 +/- 8.3 (standard error of mean (SEM)) per hour versus 1 +/- 0.6 (SEM) per hour in non-RSWA controls (p < 0.001). Patients with RSWA/PLMS-REM and non-RSWA controls had similar age and gender, 62 +/- 3 (SEM) versus 58 +/- 3 (SEM) years and 81% versus 87% men, respectively. However, psychiatric diagnosis, neurological disorders, and antidepressants use were more common among RSWA/PLMS-REM patients compared to non-RSWA controls with p = 0.0002, p = 0.0035 and p = 0.0074 respectively (Fisher’s Exact Test). Conclusion Psychiatric diagnosis, neurological disorders, and antidepressant use are more common among RSWA/PLMS-REM patients compared to non-RSWA/non-PLMS-REM controls. Further research to determine the implications of a diagnosis of RSWA/PLMS-REM for the future development of alpha-synucleinopathies are needed and currently ongoing. Support (if any):