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):
Prevalence and predictors of REM sleep without Atonia in a sleep clinic population
