REM behavior disorder (RBD) is characterized by loss of muscle atonia during REM sleep leading to more or less expressed motor activity and vocalization, typically in the context of vivid and colorful dreams often with dramatic content. Violent behavior represents a risk not only for the patient but also for his/her bed-partner.
Besides a typical medical history, the diagnosis is based on polysomnographic examination with characteristically increased electromyographic activity in the REM phase of sleep. The disorder can be primary (idiopathic) or secondary.
The secondary form is associated with use or withdrawing certain medications or with some neurological disorders, such as narcolepsy in young patients and neurodegenerative diseases in the elderly (Parkinson disease, Lewy body dementia, multiple system atrophy). The idiopathic form is supposed to be related to these neurodegenerative conditions and it can precede the development of their principal symptoms by several years.
The management of this disorder includes securing the patient’s sleeping environment – in order to avoid an injury - and pharmacological alleviation of symptoms by the use of clonazepam.