REM sleep without atonia and the relation with Lewy body disease

• Published in: Parkinsonism & related disorders 2019-10, Vol.67, p.90-98
• Main Authors: Dijkstra, Femke, Van den Bossche, Karlien, de Bruyn, Barbara, Reyn, Nathan, Viaene, Mineke, De Volder, Ilse, Cras, Patrick, Crosiers, David
• Format: Article
• Language: English
• Subjects: Dementia with Lewy bodies; Lewy body disease; Parkinson's disease; REM sleep behavior disorder; REM sleep without atonia
• ISSN: 1353-8020; 1873-5126
• DOI: 10.1016/j.parkreldis.2019.07.007

REM sleep without atonia (RSWA) is the polysomnographic finding of persistent muscle tone during REM sleep, resulting in paroxysmal phasic or tonic EMG activity. RSWA is essential for the diagnosis of REM sleep behavior disorder (RBD), but can also occur without dream-enacting behavior. Loss of atonia during REM sleep is considered as a biomarker for synucleinopathies. We will give an overview of the pathophysiology of RSWA and will highlight the diagnostic methods for RSWA. We will describe the different etiologies of RSWA and finally we will focus on the role of RSWA as biomarker for Lewy body disease. RSWA severity in isolated RBD patients is a potential predictor for early conversion to Parkinson's disease (PD) or dementia with Lewy bodies. In PD patients, RSWA severity is associated with more severe motor symptoms and disease progression. Future studies are needed to delineate the importance of isolated RSWA as prodromal marker of Lewy body disease. •Several diseases and medications are associated with REM sleep without atonia.•RSWA can occur without dream-enacting behavior.•RSWA severity increases over time in Lewy body disease.•RSWA severity is a predictor of phenoconversion to overt parkinsonism or dementia.•Isolated RSWA might be a prodromal biomarker of Lewy body disease.