January 2021 | Reviewed by: Reeba Mathew, MD and Anne M. Morse, DO
What is sleep rhythmic movement disorder?
Sleep-related rhythmic movement disorder (RMD) involves repeated body movements. They occur while drowsy or asleep. It is typically seen in children. Rhythmic humming or other sounds are sometimes made along with the body motions. These sounds can be quite loud.
Episodes often occur when your child is falling asleep or almost asleep. They may also occur at any point in the night. At times, they may even happen during quiet activities when your child is awake. Your child may be listening to music or riding in a car.
The rate may vary, but the actions are rapid. One or two motions tend to occur every one or two seconds. An episode will often last up to 15 minutes. The motions may stop when a noise, movement or voice disturbs your child. Children who are old enough to talk will usually not recall the event in the morning.
These actions are common in normal infants and children. These motions alone do not qualify as a disorder. It is only a disorder if the actions severely injure your child or greatly disturb her sleep. The noises can greatly distress other family members. It is normal for a parent to be concerned. It is important for parents to discuss your child’s actions with other caretakers, family members, or babysitters.
There are several types of RMD, including:
- Body rocking – Your child may rock her entire body while on hands and knees. She may also rock her upper body while sitting up.
- Head banging – This often occurs with your child lying face down. He lifts his head or entire upper body. Then he forcibly bangs his head back down into the pillow or mattress. This action is repeated. It may also occur when your child is sitting up. He will bang the back of his head against the wall or headboard repeatedly. Body rocking and head banging may also be combined. Your child will rock on hands and knees. At the same time, he will bang the front of his head into the wall or headboard.
- Head rolling (AKA Jactatio Capitus Nocturna) – The head is rolled back and forth. Your child is normally lying on his back.
Head banging is the most disturbing form of the problem. Typical cases in infants and toddlers pose little risk of serious injury. Strong motions can cause loud noises when your child hits the bed frame. The bed may also bang against the wall or scrape the floor.
Less common rhythmic movement forms include the following:
- Body rolling
- Leg banging
- Leg rolling