Cognition and obstructive sleep apnoea in Parkinson’s disease, effect of positive airway pressure therapy (COPE-PAP trial): protocol of a randomized controlled trial

Background: Parkinson’s disease (PD) is the second most frequent neurodegenerative disease and is associated with cognitive dysfunction. Obstructive sleep apnea (OSA) has been linked with cognitive dysfunction in the general population and in PD. Treatment with positive airway pressure (PAP), can improve cognition in the general population and in patients with other neurodegenerative diseases. However, the effect of PAP therapy on cognitive function has not been well studied in PD.Methods: This randomized controlled trial will assess the effect of 6 months of PAP therapy versus placebo on global cognitive function in PD patients with OSA and reduced baseline cognition. Secondary outcomes will include quality of life and other non-motor symptoms of PD. Exploratory outcomes will be specific domains of neurocognitive function and symptoms of REM sleep behaviour disorder.Conclusions: PD-related cognitive dysfunction often evolves towards dementia and has substantial personal, social and healthcare costs. Few interventions have been shown to improve cognition in PD to date. If positive, results from our study could prove OSA to be a new therapeutic target relevant to cognition and would support more systematic screening for OSA in PD patients with cognitive decline.Trial Registration: Trial registration number is NCT02209363.