Yuichi Inoue
Tokyo Medical University, Japan
Title: Electroencephalographic fi nding in idiopathic REM sleep behavior disorder
Biography
Biography: Yuichi Inoue
Abstract
The REM sleep behavior disorder (RBD) is a type of parasomnia manifested by vivid, oft en frightening dreams associatedrnwith motor behaviors during REM sleep, sometimes causing injuries to patients themselves or to their bed partners. Th ernpolysomnographic features of RBD include increased muscle activity during REM sleep (REM sleep without atonia). Th ernmajority of RBD-aff ected persons are older men. Th e disorder might be idiopathic (iRBD) or secondary to neurological disordersrnof various kinds. iRBD management with pharmaceutical measures is usually straightforward and eff ective. Several longitudinalrnstudies have revealed that a high proportion of iRBD patients convert to α-synucleinopathies such as Parkinson’s disease andrndementia with Lewy body disease (DLB). Considering this, many studies have been conducted to identify common clinicalrnmarkers between α-synucleinopathies and iRBD or indicators for the future development of α-synucleinopathies in iRBDrnpatients. In this context, electroencephalographic (EEG) slowing occurring while awake and asleep, which is frequently observedrnin DLB, has received much attention. Clarifi cation of the association between EEG slowing and the presence of mild cognitivernimpairment, which is also commonly seen in early stages of DLB, has been particularly expected to off er a breakthrough for thernidentifi cation of cases which might convert to α-synucleinopathies. In this article, we introduce the progress in quantitative EEGrnresearch in iRBD during the past decade. We also discuss the relationship between EEG fi ndings and cognitive decline as well asrnthe mechanisms of EEG changes or cognitive abnormalities in patients with the disorder.