REM behavior disorder (RBD) is a sleep disorder, or parasomnia, that occurs during REM sleep. A person with RBD will act out his or her dreams, often in a violent physical manner, and this can include loud shouting or grunting. There is no known cause for REM behavior disorder, which was first described in 1986.
Sleep has two main phases, which are NREM sleep and REM sleep. NREM sleep, or non-rapid eye movement sleep, has four stages and each stage has its own unique characteristics. REM sleep involves several physiological changes including increased brain activity, eye movement, accelerated respiration and muscle relaxation. This muscle relaxation includes paralysis of major voluntary muscles while the increased brain activity causes dreams.
In people who suffer from REM behavior disorder, dreams are present during REM sleep but the muscle paralysis is not. This allows them to act out their dreams intensely and sometimes violently. During REM sleep, the behaviors of a person with RBD can include talking, punching, sitting up, grabbing, jumping out of bed, sleepwalking and sleep terrors. The body can also tense up very rigidly for seconds or even minutes. These activities usually, but not always, are confined to the bed and its surrounding area, and sometimes the person’s sleeping partner can be injured as a result.
The person with RBD will usually remember little, if anything at all, of these activities unless they happen to injure themselves and wake up. They can, however, usually vividly recall the dreams that they were having during the episode. These dreams usually involve physical or violent activities such as fighting, being attacked or running.
REM behavior disorder has been found to be most prevalent among males between the ages of 15 and 100. Only a tenth of those who suffer from RBD are female. The cause of REM sleep behavior disorder is unknown, but the onset is often associated with several degenerative neurological conditions such as Parkinson’s disease and multi-system atrophy. Sometimes a more acute form of REM behavior disorder can also result from alcohol or drug withdrawal. The treatments for REM behavior disorder include sleep monitoring, drug therapy, and ruling out possible other causes.