Abstract
REM sleep without atonia (RSWA) is the polysomnographic (PSG) hallmark of rapid eye movement (REM) sleep behavior disorder (RBD), a feature essential for the diagnosis of this condition. Several additional neurophysiological aspects of this complex disorder have also recently been investigated in depth, which constitute the focus of this narrative review, together with RSWA. First, we describe the complex neural network underlying REM sleep and its muscle atonia, focusing on the disordered mechanisms leading to RSWA. RSWA is then described in terms of its polysomnographic features, and the methods (visual and automatic) currently available for its scoring and quantification are exposed and discussed. Subsequently, more recent and advanced neurophysiological features of RBD are described, such as electroencephalography during wakefulness and sleep, transcranial magnetic stimulation, and vestibular evoked myogenic potentials. The role of the assessment of neurophysiological features in the study of RBD is then carefully discussed, highlighting their usefulness and sensitivity in detecting neurodegeneration in the early or prodromal stages of RBD, as well as their relationship with other proposed biomarkers for the diagnosis, prognosis, and monitoring of this condition. Finally, a future research agenda is proposed to help clarify the many still unclear aspects of RBD.
Highlights
For the International Classification of Sleep Disorders 3rd Edition (ICSD-3) [1], rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia manifested by vivid, often frightening dreams accompanied by simple or complex motor behaviors during REM sleep
Several additional neurophysiological aspects have recently been investigated in depth, which will constitute the focus of this narrative review together with REM sleep without atonia (RSWA)
Both basic and clinical evidence have indicated that RBD results from the breakdown of a broad network underlying REM sleep atonia, which provides a dynamic model of interaction between the brainstem and both rostral and caudal CNS structures [31]
Summary
For the International Classification of Sleep Disorders 3rd Edition (ICSD-3) [1], rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia manifested by vivid, often frightening dreams accompanied by simple or complex motor behaviors during REM sleep. Idiopathic (or isolated) RBD (iRBD) is an established early manifestation of a neurodegenerative disease, especially synucleinopathy [3]. RBD can be found in a large proportion of both children and adults with narcolepsy, representing a form of REM sleep motor behavior dyscontrol [4,5], and it seems to be a phenotype distinct from iRBD, with less marked sex predominance, more elementary and less complex movements and less violent behavior in REM sleep, younger age of onset, and orexin deficiency (a feature of narcolepsy type 1) [6,7]. RSWA remains the most important neurophysiological aspect, being necessary for the diagnosis of RBD [9]. Several additional neurophysiological aspects have recently been investigated in depth, which will constitute the focus of this narrative review together with RSWA
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
