Impact of sleep-related breathing disorder on motor and non-motor symptoms in multiple system atrophy

Introduction Although several studies suggested that sleep-related breathing disorder (SRBD) is a frequent symptom of multiple system atrophy (MSA), whether SRBD has influence on the motor and non-motor symptoms of MSA is unknown. Methods A total of 40 MSA patients and 40 healthy volunteers (HVs) underwent video-polysomnography (PSG) in the current study. All the MSA individuals were assessed using the Epworth Sleepiness Scale (ESS), Unified Multiple-System Atrophy Rating Scale (UMSARS), Hamilton Depression Scale (HAMD), Hamilton Anxiety Scale, Frontal assessment battery (FAB), Parkinson's Disease Questionnaire-39 (PDQ-39), and the Montreal Cognitive Assessment (MoCA). Results We found apnea-hypopnea index (AHI) of the MSA patients recorded by PSG was 16.4 +/- 20.2. SRBD was found in 65% of the MSA patients (26/40), which was significantly higher than HVs (8/40, 20%) (p = 0.0001). Compared to the MSA patients without SRBD, MSA individuals with SRBD showed higher total UMSARS, UMSARS-II, FAB, and HAMD scores, more frequent occurrence of excessive daytime sleepiness, hypopneas, longer mean times for hypopneas, and obstructive sleep apnea (OSA), as well as longer time for OSA. This study suggested that SRBD is frequently seen in MSA patients. Conclusion MSA individuals with SRBD are prone to be severe motor deficits, depression, frontal lobe dysfunction, and excessive daytime sleepiness.