A disorder characterized by episodes of vigorous and often violent motor activity during rem sleep (sleep, rem). The affected individual may inflict self injury or harm others, and is difficult to awaken from this condition. Episodes are usually followed by a vivid recollection of a dream that is consistent with the aggressive behavior. This condition primarily affects adult males. (From Adams et al., Principles of Neurology, 6th ed, p393). The disease is Monarch Disease Ontology term MONDO_0005937 (REM sleep behavior disorder). Also known as: rapid eye movement sleep behavior disorder, rapid eye movement sleep behaviour disorder.