Obstructive sleep apnoea during rapid-eye movement sleep is predictive for response to treatment in patients with parasomnia

Background: Obstructive sleep apnoea during rapid-eye movement sleep (REM-OSA) is a distinct phenotype of obstructive sleep apnoea (OSA) which is associated with higher burden of cardiovascular disease. However, less is known its association with parasomnia symptoms which could also be triggered by OSA. We aimed to correlate the presence of REM-OSA with REM and NREM parasomnias as well as their response to treatment. Methods: Polysomnographic data and medical charts of 61 patients complaining of symptoms of parasomnia were analysed. REM-OSA was defined as apnoea-hypopnea index in REM (REM-AHI) ≥5/hour but AHI in NREM (NREM-AHI) <5/hour. Patients with REM-OSA were compared to those who had both REM-AHI and NREM-AHI <5/hour. The diagnoses of REM, NREM and overlap parasomnia were based on medical history and polysomnographic findings. Results: Twenty-five patients met the criteria for REM-OSA. Neither the presence of REM-OSA or REM-AHI were associated with REM, NREM or overlap parasomnias. Thirteen patients were treated with clonazepam, 34 with melatonin and 4 with continuous positive airway pressure. Interestingly, whilst the presence of REM-OSA was associated with symptoms improvement due to clonazepam (33% vs. 0%, REM-OSA vs. controls, p=0.02), patients with REM-OSA showed inferior response to melatonin (improvement in 11% vs. in 71%, REM-OSA vs. controls, p<0.01). Conclusions: REM-OSA does not seem to be associated with a particular type of parasomnia. However, its presence may be predictive for treatment response and may help to tailor personalised treatment in patients with parasomnia.