CPAP therapy for RBD symptoms in patients with concurrent OSA: a systematic review

REM sleep behavior disorder (RBD) frequently co-occurs with obstructive sleep apnea (OSA), with up to 90% of RBD patients having concurrent OSA. OSA-related sleep fragmentation may exacerbate RBD symptoms through disruption of REM sleep architecture. While continuous positive airway pressure (CPAP) is the gold standard for OSA treatment, its effects on RBD symptoms are not well characterized. This systematic review evaluated CPAP therapy effectiveness for improving RBD symptoms in patients with concurrent RBD and OSA. We conducted a systematic review in accordance with PRISMA guidelines, searching MEDLINE, EMBASE, and Cochrane databases from inception through July 2025. Studies were eligible if they evaluated the effect of CPAP on RBD symptoms in patients with both disorders, used validated diagnostic criteria, and reported relevant treatment outcomes. Study quality was assessed using the Newcastle-Ottawa Scale. Three observational studies comprising 377 patients met inclusion criteria. CPAP therapy was associated with variable improvement in RBD symptoms, with response rates ranging from 45.8% to 74.2%. Potential predictive factors for treatment success included an apnea-hypopnea electromyography (AH-EMG) activity ratio ≥ 15% (OR = 10.146, 95% CI: 1.2-83.3, p = 0.032) and a REM apnea-hypopnea index (AHI) ≥ 10 events per hour. A dose-response relationship was observed, with adherent CPAP users showing 35.0% reduction in dream enactment behaviors compared with 13.3% among non-users. Preliminary evidence suggests CPAP therapy may provide clinically meaningful improvement in RBD symptoms for patients with concurrent OSA. However, the limited evidence base consisting of only observational studies precludes definitive conclusions. The identified predictive factors and adherence-response relationship warrant further investigation through randomized controlled trials.

The online version contains supplementary material available at 10.1007/s41105-025-00616-6.