Sleep-Related Rhythmic Movement Disorder (RMD)

Sleep-related rhythmic movement disorder (RMD) is a neurological condition that involves repetitive movements before or during sleep. Movements may also include body rocking, head banging, or rolling and can last minutes to hours.

This condition commonly affects children and rarely persists into adolescence or adulthood. In many cases, no treatment is required. Learn about rhythmic movement disorder, including treatment options to keep your child safe.

Symptoms of 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 a 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. Of those who develop the condition, only about 5% continue to have symptoms at 5 years of age. It rarely persists into adulthood.

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:

• Attention deficit hyperactivity disorder (ADHD)
• Tourette syndrome
• Autism
• Rett syndrome
• Angelman syndrome
• Sleep apnea

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

Diagnosis

Many parents may recognize the movements in their children. Talk with your pediatrician about your observations and getting a more thorough sleep history. 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.

Your pediatrician may suggest a few tests to differentiate the cause of the movements. A routine electroencephalogram (EEG) may be performed. This test measures the electrical activity of the brain. Sleep may also be formally studied with an overnight sleep study (polysomnogram) that may include the EEG as part of it.

RMD Treatment Options

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 away from the bedroom walls or other objects. Some children with severe headbanging 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. Some people may be responsive to melatonin, which can help you naturally control your sleep cycle. Other relaxation techniques have also been reported to be effective.

In 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 milder.

If you notice your child having uncontrolled movements during sleep, check with your pediatrician to discuss if further evaluation is necessary.