Comparison Study of Polysomnographic Features in Multiple System Atrophy-cerebellar Types Combined with and without Rapid Eye Movement Sleep Behavior Disorder

Clinical features of multiple system atrophy with or without rapid eye movement behavior disorder: a cross-sectional study in southwest China

OBJECTIVE

The aim of this study was to investigate the prevalence of rapid eye movement behavior disorder (RBD) in Chinese patients with multiple system atrophy (MSA) and to compare motor and non-motor symptoms and sleep disturbance of MSA patients with and without RBD.

METHODS

A total of 55 patients who were consecutively admitted to West China Hospital of Sichuan University from 2016 to 2019 and subsequently diagnosed with probable MSA were enrolled in this cross-sectional study. The diagnosis of RBD was based on the results of video polysomnography (PSG) and a history of abnormal sleep-related behaviors. The patients were divided into two groups: those with RBD and those without. These two groups were then compared in terms of severity of motor symptoms (Unified Multiple System Arophy Rating Scale) and non-motor symptoms (Non-Motor Symptoms Scale, Mini-Mental State Examination score, Epworth Sleepiness Scale, Fatigue Severity Scale, Pittsburgh Sleep Quality Index, REM Sleep Behavior Disorder Screening Questionnaire, Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale) and sleep parameters as recorded on PSG.

RESULTS

Of the 55 patients (35 males), 18 (33%, 13 males) were diagnosed with RBD. Patients with or without RBD did not differ in demographic characteristics, clinical features, or sleep parameters based on PSG.

CONCLUSION

There was no difference in motor and non-motor symptoms between MSA patients with or without RBD, indicating that the presence of RBD may not be significantly associated with the severity of motor or non-motor dysfunction in MSA.

Tonic Electromyogram Density in Multiple System Atrophy with Predominant Parkinsonism and Parkinson's Disease

BACKGROUND

Both Parkinson's disease (PD) and multiple system atrophy (MSA) have associated sleep disorders related to the underlying neurodegenerative pathology. Clinically, MSA with predominant parkinsonism (MSA-P) resembles PD in the manifestation of prominent parkinsonism. Whether the amount of rapid eye movement (REM) sleep without atonia could be a potential marker for differentiating MSA-P from PD has not been thoroughly investigated. This study aimed to examine whether sleep parameters could provide a method for differentiating MSA-P from PD.

METHODS

This study comprised 24 MSA-P patients and 30 PD patients, and they were of similar age, gender, and REM sleep behavior disorder (RBD) prevalence. All patients underwent clinical evaluation and one night of video-polysomnography recording. The tonic and phasic chin electromyogram (EMG) activity was manually quantified during REM sleep of each patient. We divided both groups in terms of whether they had RBD to make subgroup analysis.

RESULTS

No significant difference between MSA-P group and PD group had been found in clinical characteristics and sleep architecture. However, MSA-P patients had higher apnea-hypopnea index (AHI; 1.15 [0.00, 8.73]/h vs. 0.00 [0.00, 0.55]/h, P = 0.024) and higher tonic chin EMG density (34.02 [18.48, 57.18]% vs. 8.40 [3.11, 13.06]%, P < 0.001) as compared to PD patients. Subgroup analysis found that tonic EMG density in MSA + RBD subgroup was higher than that in PD + RBD subgroup (55.04 [26.81, 69.62]% vs. 11.40 [8.51, 20.41]%, P < 0.001). Furthermore, no evidence of any difference in tonic EMG density emerged between PD + RBD and MSA - RBD subgroups (P > 0.05). Both disease duration (P = 0.056) and AHI (P = 0.051) showed no significant differences during subgroup analysis although there was a trend toward longer disease duration in PD + RBD subgroup and higher AHI in MSA - RBD subgroup. Stepwise multiple linear regression analysis identified the presence of MSA-P (β = 0.552, P < 0.001) and RBD (β = 0.433, P < 0.001) as predictors of higher tonic EMG density.

CONCLUSION

Tonic chin EMG density could be a potential marker for differentiating MSA-P from PD.