Prevalence of obstructive sleep apnoea in REM behaviour disorder: response to continuous positive airway pressure therapy

OBJECTIVES: Rapid eye movement behaviour disorder (RBD) is a parasomnia in which there is loss of muscle atonia during rapid eye movement (REM) sleep, resulting in dream enactment. The aims of this study were to determine the prevalence of obstructive sleep apnoea (OSA) in RBD patients and determine whether continuous positive airway pressure (CPAP) therapy improved RBD symptoms in patients with concomitant RBD and OSA.

METHODS: A questionnaire was mailed to 120 patients identified from a tertiary sleep centre with RBD meeting full International Classification for Sleep Disorders-3 (ICSD-3) criteria. Patients were diagnosed as having OSA if they had an apnoea-hypopnea index (AHI) ≥ 5. The questionnaire focused on CPAP-use, compliance and complications. Standard statistical analysis was undertaken using SPSS (v.21, IBM).

RESULTS: One hundred and seven of the potential participants (89.2%) had an OSA diagnosis. Out of 72 who responded to the questionnaire, (60%) 27 patients were using CPAP therapy. CPAP therapy improved RBD symptoms in 45.8% of this group. Despite this positive response to treatment in nearly half of CPAP-users, there was no significant difference in subjective or objective CPAP compliance between those who reported RBD improvement and those who did not. Subjective compliance with CPAP was over-reported, with mean usage being 7.17 ± 1.7 h per night compared to objective mean compliance of 5.71 ± 1.7.

CONCLUSIONS: OSA is a very common co-morbidity of RBD. CPAP therapy might improve self-reported RBD symptoms further, in addition to standard RBD treatment. However, further research into its topic is necessary.