A randomized controlled trial of 94 Parkinson's disease patients with obstructive sleep apnea found that 6 months of positive airway pressure (PAP/CPAP) therapy improved global cognition compared to placebo nasal dilator strips. The adjusted intention-to-treat analysis showed a 1.44-point MoCA improvement in the PAP group versus controls. Per-protocol analyses confirmed a 1.43-point benefit among adherent users. Secondary gains included better depression scores, sleep quality, and performance on executive and psychomotor tasks. Motor function also improved significantly in per-protocol analyses. This is the largest and longest RCT of OSA treatment in any neurodegenerative disease, suggesting that screening Parkinson's patients for sleep apnea and treating it could slow cognitive decline.
