Immediate Effect of Continuous Positive Airway Pressure Therapy on Sleep and Respiration in Patients with Multiple System Atrophy and Sleep‐Disordered Breathing.

Background: Sleep‐disordered breathing (SDB; including stridor and sleep apnea syndromes) is frequent in multiple system atrophy (MSA), but the immediate effect of continuous positive airway pressure (CPAP) therapy is incompletely determined. Objective: We sought to evaluate the acute effect and safety of CPAP therapy on SDB and sleep architecture, as well as the clinical characteristics of nonresponders to CPAP therapy. Methods: The measures of 63 consecutive patients with MSA who underwent a video‐polysomnography during two consecutive nights (a first night in ambient air, a second night with or without CPAP, depending on the presence of SDB and availability of CPAP) in routine care were retrospectively collected. Linear mixed models assessed the two‐night change in sleep and respiratory measures, comparing those with and without the CPAP therapy on the second night. Results: SDB was frequent and mainly associated with the cerebellar phenotype. The introduction of CPAP had immediate benefits, including the normalization of the apnea–hypopnea index and a resolution of stridor in more than two‐thirds of the cases, decreased arousal index, and increased rapid eye movement sleep. CPAP therapy was well tolerated, and only two patients had emergent central apneas. Nonresponse to CPAP was generally associated with more severe motor disease. Conclusions: CPAP seems a well‐tolerated and effective therapy in patients with MSA and SDB in the short term. This treatment shows remarkable immediate benefits by objectively improving both respiratory disturbances and sleep architecture. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]