Selective Polysomnographic Findings in REM Sleep Behavior Disorder (RBD) and Parkinson’s Disease

Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia mainly characterized by REM sleep without atonia, and it has been identified as one of the main risk factors for later development of parkinsonism including Parkinson’s disease (PD) and Lewy body dementia. Despite the main electrophysiological change during polysomnography of RBD is found in muscular activity, in this chapter, we present an overview of other electrophysiological changes that characterize RBD and PD, such as electroencephalographic slowing during REM, micro- and macrostructure sleep alterations (i.e., electrooculographic changes, sleep spindle alterations, increased sleep fragmentation, among others), and finally abnormalities in evoked potentials. These findings support the hypothesis of early involvement of the brain stem in alpha-synucleinopathies and therefore represent useful electrophysiological biomarkers for identification of parkinsonism’s development.