Rhythmic Movement Disorder

Rhythmic Movement Disorder, also referred to as jactatio capitis nocturna, is a condition characterized by repetitive banging or rocking motions just before and during light sleep. This condition occurs primarily in infants and young children, although adults can be affected as well and may be related to the lack of contact in infancy. While rarely harmful, it can be alarming or confusing to parents or others who witness it occurring.

Symptoms

The symptoms of this condition are characterized by repetitive movements of certain areas of the body, usually the head and neck. There are varying types of movement which may be seen, including:

• The head is forcibly moved in a back and forward direction - head-banging type
• The head is moved laterally while in a supine (lying on the back, face up) position - head-rolling type
• The whole body is rocked while on the hands and knees - body-rocking type
• The whole body is moved laterally while in a supine position - body-rolling type

RMD most commonly affects otherwise healthy children but may also be seen in association with autism and other developmental disabilities.

Causes

There is very little literature or consensus available as to the cause of this condition, but there seems to be two distinct versions of the condition: one is associated with hyperactivity and certain autistic tendencies; whilst the other is a harmless behaviour found in normally developing children. Some parents may become concerned that the behaviour is intended to be self-harming (eg. banging the head on the mattress repeatedly), although observations of people with this condition indicate that this is very rarely the case.

When asked by adults why they "rock" themselves to sleep it has been offered that it is a calming and soothing way to fall asleep, often reminding them of being an infant and being coddled to sleep by a parent or caregiver. It is often a learned response when babies are taught to "self soothe" and also provides the child warmth through body movement.

Some adult RMD sufferers (those with autistic and intellectual penchant) commonly possess high mental focus. RMD may serve as a way to break that concentration and lull them into a regular REM state during periods of light sleep. A smaller percentage of these RMD adults will also experience cycles of extreme sleeplessness throughout their lifetime (see insomnia, hypersomnia, and narcolepsy).

Another theory draws parallels between rhythmic sleep movements and other rhythmic activities that promote relaxation or pleasure such as the repetitive movements seen in various dance forms, certain physical sports activities (i.e. running, rowing, etc.), and some meditative and religious practices (i.e. practices where adherents engage in stereotypic motion such as rocking back and forth or swaying, sometimes for extended time periods). The theory suggests that rhythmic physical movement may cause in some the release of neurochemicals that either are soothing or at least create a dependency over time given sufficient exposure.

Some “sleep rockers” report a profound sense of relief when they allow themselves to engage in their pre-sleep movements and conversely great agitation when they attempt to “restrain” themselves from their sleep movements. The degree and description of both relief and agitation reported by some with rhythmic sleep movements bears striking resemblances to reports from dancers, runners, or those whose religious practices include rhythmic movement who have been unable to engage in their desired activity.

Treatment

Although sometimes disconcerting for parents to witness, RMD is usually a benign behavior which typically resolves itself by age five. For most affected children, RMD is a self-limited condition that does not require treatment. For youngsters exhibiting particularly violent movements, use of protective padding in the crib or bed is often helpful.

In some cases in RMD can continue into adulthood, potentially interfering with normal social events.

External links

• Study on use of impiramine in JCN

References

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