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Rhythmic movement disorder (RMD) describes a neurological condition where a person rocks or moves their body in a repetitive manner just before or while falling asleep.
Rhythmic movement disorder (RMD) describes a neurological condition where a person rocks or moves their body in a repetitive manner just before or while falling asleep. The movements typically involve the upper torso, neck, arms, or head. RMD is typically experienced by children and most cases disappear naturally by age 5. The disorder was first described in 1905 and referred to as jactatio capitis nocturna or rhythmie du sommeil.
A person with RMD moves part of their in a repetitive manner, especially movements involving the neck and upper torso. This happens just before sleep or during stage 1 of non-REM light sleep. Sometimes the movements can continue into REM sleep, but it’s possible those movements are actually symptoms of REM behavior disorder. The episodes last under 15 minutes, and the movement themselves are rapid, occurring at a rate of 1 to 2 seconds.
Rhythmic movement disorder most often appears as one of the three types of body movement described below, or as a combination of two:
During any of these movements, the person may also hum loudly or create other loud noise by their body coming into contact with parts of the bed, or the bed moving on the floor or into other furniture as a result of the body rocking movement.
Body rocking typically occurs at night, but may occur during the day if the person is drowsy and in a quiet environment. The movement typically stops once the person enters the second stage of light sleep, or if they are roused by another sound or movement.
Does your child bang their head while sleeping? He or she may have rhythmic movement disorder.
Sleep-related rhythmic movement disorder is common in young children, and appears to affect boys and girls at the same rate. About 60 percent of nine-month-old infants experience it to some degree. By age four, only 18 percent of children still have these movements, and RMD usually disappears naturally by age 5. Studies have estimated RMD continues in 6 percent of 5-year-olds and in 3 percent of 13-year-olds. At these later ages the condition is rare enough that it can be considered a sleep disorder, although it is still benign in the large majority of cases.
Most children and adults who have rhythmic movement disorder are healthy, although the condition is more common in children with autism and other developmental disabilities.
One well-intentioned mistake parents often make when their child is experiencing a rocking episode is to wake them up. While this interrupts the immediate episode, the child will just commence rocking as they begin to fall asleep again. Unless your child is at immediate risk of hurting themselves (falling off the bed onto a hard surface, or hitting an unpadded bed rail, for example), you should not intervene. If the movements are particularly violent, invest in the sleep products recommended for RMD explained below.
Adults who have RMD may find it embarrassing and irritating to others. As long as it’s not causing physical harm, experts suggest using extra padding in the bed and letting your sleeping partner know about it beforehand so as not to alarm them. RMD is much less common in adults than other parasomnias such as sleepwalking or sleep talking.
This video from The Neurology Journal shows a 39-year-old otherwise healthy man who experiences head rolling.
Typically, most adults who have rhythmic movement disorder have had it since childhood. When it presents itself at an older age, studies have suggested it may be caused by an injury to the central nervous system.
For most affected children, RMD is a self-limiting condition that does not require treatment. Most children who rock themselves to sleep grow out of it by age 5.
In extreme cases, doctors sometimes use the anticonvulsant drug clonazepam (which can be addictive) or the antidepressant citalopram to slow or stop the movements. Before prescribing, your doctor will have your child undergo a polysomnogram test, during which your doctor will monitor your child’s brain waves, heartbeat, and breathing overnight while asleep.
For those who suffer from particularly violent body rolling or body rocking movements, protective padding in the crib or bed can prevent injuries. Assistive bedding devices that may minimize injury for people with RMD include:
Practicing good sleep hygiene and maintaining a regular sleep schedule are both recommended as a preventative measure. Controlled sleep restriction has also been found to have some benefit.
Because rocking to sleep may be indicative of another neurological disorder, it is important to seek evaluation from your doctor or pediatrician to rule out anything else that may be causing the body rocking, such as nocturnal seizures.