Nocturnal stridor in multiple system atrophy: video-polysomnography and clinical features

Abstract Background Nocturnal stridor is an important issue in patients with multiple system atrophy (MSA). However, little is known about the polysomnographic findings and clinical features of patients with MSA with nocturnal stridor, and its clinical implications. Objectives We aimed to investigate the video-polysomnography findings (VPSG) and clinical features associated with nocturnal stridor in patients with MSA. Methods We retrospectively analyzed the clinical data of patients with MSA (n = 49) who underwent overnight VPSG for evaluation of sleep-disordered breathing. The presence of nocturnal stridor was confirmed based on overnight VPSG findings. The patients’ clinical data, including VPSG findings and clinical features, were compared between the patients with MSA with and without nocturnal stridor. Results Nocturnal stridor was present in 31 (63.3%) patients with MSA. The patients with stridor showed significantly higher apnea-hypopnea, respiratory disturbance, and oxygen desaturation indices than those without stridor (P = 0.024, P = 0.049, and P = 0.006, respectively). The patients with stridor had severer axial motor features, impaired activities of daily living, and a longer disease duration than those without stridor (P = 0.012, P = 0.036, and P = 0.003, respectively). However, there were no significant differences in sex, age at disease onset, MSA subtype, parkinsonian features, cerebellar ataxia, residual urine volume, and systolic and diastolic blood pressure change between the groups. Conclusions MSA with nocturnal stridor is associated with severe hypoxemia during sleep, severe axial motor features, impaired activities of daily living, and a long disease duration.