REM sleep behavior disorder as a prodromal stage of α-synucleinopathies. Symptoms, epidemiology, pathophysiology, diagnosis and therapy

Rapid eye movement (REM) sleep behavior disorder (RBD) is defined as a parasomnia characterized by loss of REM sleep-associated atonia and the presence of motor activity during dreaming typically presenting with an aggressive dream content. Epidemiological data on the prevalence of RBD are insufficient but it can be idiopathic or symptomatic. A video-audio polysomnography is essential for diagnosis. Clonazepam and melatonin are available as pharmaceutical treatment. Recent studies demonstrated that individuals suffering from idiopathic RBD carry a high specific risk (up to 80%) for developing a neurodegenerative disorder of the alpha-synucleinopathy type (e. g. Parkinson's disease, dementia with Lewy bodies and multiple system atrophy) within 10-20 years. The current article provides a short overview of symptoms, epidemiology, pathophysiology, diagnosis and therapy of RBD.