Impaired Dynamic Cerebral Autoregulation Across the REM Sleep Behavior Disorder Spectrum: Evidence From Isolated REM Sleep Without Atonia to Parkinson's Disease With RBD

Objectives

Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by REM sleep without atonia (RSWA) and dream-enactment behaviors and is recognized as a prodromal manifestation of α-synucleinopathies. Isolated RSWA (iRSWA) has been proposed as a potential early stage within the RBD spectrum, although its clinical and physiological significance remains incompletely understood. This study aimed to investigate alterations in sleep architecture, phasic muscle activity, and dynamic cerebral autoregulation (dCA) across the spectrum from iRSWA to isolated RBD (iRBD) and Parkinson's disease with RBD (PD + RBD).