Subjective and objective features of sleep disorders in multiple system atrophy

Objective To investigate the subjective and objective sleep disorders in patients with multiple system atrophy (MSA). Methods Thirty MSA patients and 25 age-and-sex matched controls were enrolled. Sleep disorders were assessed by Pittsburgh Sleep Quality Index (PSQI), Parkinson's Disease Sleep Scale-2 (PDSS-2), and polysomnography (PSG). Results Twenty-nine (96.7%) patients complained of sleep disorders. The PSQI and PDSS-2 scores were significantly higher in MSA group than those in control group (PSQI: 9.37±4.60 vs 5.36±2.86, t=-3.934, P<0.01; PDSS-2: 15.60±10.02 vs 5.48±2.74, t=-5.300, P<0.01). Some parameters of sleep scales were correlated with advancing ages and the severity of symptoms in MSA with predominant parkinsonism (MSA-P) patients. PSG revealed reduced total sleep time (TST) and sleep efficiency (SE) and higher periodic limb movement in sleep (PLMS) index in MSA patients. Rapid eye movement sleep disorder (RBD) was confirmed by PSG in 24(80.0%) patients, with only 2 of whom manifesting violent behaviors. The patients with MSA-P showed higher PDSS-2 scores than patients with MSA with predominant cerebellar ataxia (MSA-C; 17.79±10.01 vs 6.83±2.40, t=4.834, P<0.01). Conclusions Sleep disorders are common in MSA patients. The sleep structure impairments mainly consist of reduced TST and SE with the proportion of sleep stages unchanged. RBD occurs frequently while the symptom is usually mild. PLMS is not rare, and the PLMS index is high. The subjective sleep quality in MSA-P patients was correlated with the severity of parkinsonian symptoms and poorer than that in MSA-C patients. Key words: Multiple system atrophy; Sleep disorders; Polysomnography; Sleep, REM; Case-control studies