Comparison of the clinical features of rapid eye movement sleep behavior disorder in patients with Parkinson's disease and multiple system atrophy

Aims: The aim of this study was to evaluate differences in the clinical presentation and polysomnographic characteristics of rapid eye movement sleep behavior disorder (RBD) between patients with Parkinson's disease (PD) and those with multiple system atrophy (MSA). Methods: We conducted clinical interviews examining RBD symptoms, including violent and non‐violent behaviors, in 49 patients with PD and 16 patients with MSA (as well as their bed partners) and performed polysomnography on all subject patients. Results: Twenty‐seven patients with PD (55.1%) and 11 patients with MSA (68.8%) had rapid eye movement sleep without atonia (RWA) on polysomnogram. The relative amounts of RWA were quite similar between the two groups. For most of the RWA‐positive patients in both groups, RBD symptoms remained non‐violent or silent. RBD symptoms in PD patients seemed to increase with the course of PD, while most of the RBD symptoms in the MSA patients occurred just prior to or at the onset of MSA and then disappeared within a short period. Conclusion: Although PD and MSA frequently accompany RWA, RBD symptoms often remain non‐violent or silent. Differences in the course of RBD symptoms in patients with PD and MSA may reflect the difference in the degeneration process of the two disorders.