What Is Sleep-related Rhythmic Movement Disorder (RMD)?

Rocking, Head Banging May Represent Self-Soothing in Children

Rocking or head banging movements may be observed as a child falls asleep and can represent rhythmic movement disorder (RMD)
Rocking or head banging movements may be observed as a child falls asleep and can represent rhythmic movement disorder (RMD). Getty Images

If your child rocks or rhythmically moves part of her body just before or even during sleep, this may represent a condition called sleep-related rhythmic movement disorder (RMD). This condition may even persist in adults. What is RMD? What conditions are associated with it and what similar disorders should be ruled out? Learn about rhythmic movement disorder, including treatment options to keep your child safe.

The Findings in Rhythmic Movement Disorder

Rhythmic movement disorder (RMD) may be observed in young children during the period just prior to or during sleep. During this period, an affected child may rock or move part of the body in a rhythmic manner. This may involve the arm, hand, head, or trunk. Other behaviors such as head banging or rolling may be observed.

Although these movements may be relatively mild and constitute a form of self-soothing to ease into sleep, they can also be more extreme. More violent movements can occur and injuries may even result.

The condition is sometimes referred to as jactatio capitis nocturna or rhythmie du sommeil, which refer to the original descriptions of the condition from 1905.

When Does Rhythmic Movement Disorder Occur?

Children with rhythmic movement disorder may develop the condition before the age of 3 years. In most cases, the symptoms fade away as the child becomes older.

It rarely may persist in adults.

RMD typically occurs early during the sleep-onset period, most commonly during light or non-REM sleep. The movements typically diminish during stage 2 of sleep. It may also occur during REM, however, which might make it difficult to distinguish from REM behavior disorder.

There are a number of other conditions that are associated with RMD. These include:

The presence of the movement does not necessarily mean that the child is likely to develop any other disorders.

How Is Rhythmic Movement Disorder Diagnosed?

Many parents may recognize the movements in their children. It may be important to speak with a pediatrician about your observations and a more thorough sleep history can be obtained. There are a few other conditions that might mimic RMD and these may require distinct treatments.

Uncontrolled movements of part of the body may occur as part of a nocturnal seizure. Contractures of muscles, often called dystonia, may also appear similar to rhythmic movement disorder. There are certain sleep disorders in children that might involve movements, including parasomnias and confusional arousals. In addition, other behavioral problems may manifest with symptoms similar to RMD.

Some medications may also cause excessive movements during the period surrounding sleep and these should be considered. If your child takes medications to treat allergies, vomiting, and certain psychiatric conditions (including antidepressants and neuroleptics), these may be implicated as a possible cause. In these cases, stopping the medication after discussing it with your pediatrician may relieve the movements.

It may be necessary to perform a few tests to differentiate the cause of the movements. A routine electroencephalogram (EEG) may be performed. Sleep may be formally studied with a polysomnogram that may include the EEG as part of it.

What Treatment Options Exist from Rhythmic Movement Disorder?

There are steps that can be taken to minimize the chance of your child harming herself during these movements.

First, it is important to maintain a regular sleep schedule and observe better sleep guidelines for children. These steps will ensure quality sleep and prevent exacerbating factors such as sleep deprivation.

When the movements are more extreme or violent, resulting in self-injury, it may be necessary to take certain safety precautions. It may be necessary to move the mattress onto the floor way from the bedroom walls or other objects. Some children with severe head banging sleep in a protective helmet.

In some instances, sedating medications may be used to minimize the movements. As an example, the medication clonazepam, which is often used to treat anxiety, has been used. Other relaxation techniques have also been reported to be effective.

It most cases, though rhythmic movement disorder may be distressing to observe, it is relatively harmless. Children are not typically bothered by it. As most outgrow the condition, it may not require long-term treatment. Even if it persists, it may not be particularly bothersome to the person affected or others, especially if the movements are more mild.

If you witness uncontrolled movements during sleep in your child, you may wish to start by checking in with your pediatrician to discuss if further evaluation is necessary.

Sources

Durmer, J.S. et al. "Pediatric Sleep Medicine." Continuum Lifelong Learning Neurol 2007;13(3):176.

Kohyama, J. et al. "Rhythmic Movement Disorder: Polysomnographic Study and Summary of Reported Cases." Brain Dev 2002;24(1):33-38.

Stepanova, I. et al. "Rhythmic Movement Disorder in Sleep Persisting into Childhood and Adulthood." Sleep 2005;28(7):851-857.

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