Rhythmic movement disorder

Rhythmic movement disorder (or RMD) is a neurological disorder characterized by involuntary (however may sometimes be voluntary), repetitive movements of large muscle groups immediately before and during sleep often involving the head and neck. It was independently described first in 1905 by Zappert as jactatio capitis nocturna and by Cruchet as rhythmie du sommeil. The majority of RMD episodes occur during NREM sleep, although REM movements have been reported. RMD is often associated with other psychiatric conditions or mental disabilities. The disorder often leads to bodily injury from unwanted movements. Because of these incessant muscle contractions, patients’ sleep patterns are often disrupted. It differs from Restless Legs Syndrome in that RMD involves involuntary muscle contractions before and during sleep while Restless Legs Syndrome is the urge to move before sleep. RMD occurs in both males and females, often during early childhood with symptoms diminishing with age. Many sufferers also have other sleep related disorders, like sleep apnea. The disorder can be differentially diagnosed into small subcategories, including sleep related bruxism, thumb sucking, hypnagogic foot tremor, and rhythmic sucking, to name a few. In order to be considered pathological, the ICSD-II requires that in the sleep-related rhythmic movements should “markedly interfere with normal sleep, cause significant impairment in daytime function, or result in self-inflicted bodily injury that requires medical treatment (or would result in injury if preventive measures were not used)”. Rhythmic movement disorder (or RMD) is a neurological disorder characterized by involuntary (however may sometimes be voluntary), repetitive movements of large muscle groups immediately before and during sleep often involving the head and neck. It was independently described first in 1905 by Zappert as jactatio capitis nocturna and by Cruchet as rhythmie du sommeil. The majority of RMD episodes occur during NREM sleep, although REM movements have been reported. RMD is often associated with other psychiatric conditions or mental disabilities. The disorder often leads to bodily injury from unwanted movements. Because of these incessant muscle contractions, patients’ sleep patterns are often disrupted. It differs from Restless Legs Syndrome in that RMD involves involuntary muscle contractions before and during sleep while Restless Legs Syndrome is the urge to move before sleep. RMD occurs in both males and females, often during early childhood with symptoms diminishing with age. Many sufferers also have other sleep related disorders, like sleep apnea. The disorder can be differentially diagnosed into small subcategories, including sleep related bruxism, thumb sucking, hypnagogic foot tremor, and rhythmic sucking, to name a few. In order to be considered pathological, the ICSD-II requires that in the sleep-related rhythmic movements should “markedly interfere with normal sleep, cause significant impairment in daytime function, or result in self-inflicted bodily injury that requires medical treatment (or would result in injury if preventive measures were not used)”. Most RMD symptoms are relatively passive and do not cause any pain. Many patients are often unaware that an episode is occurring or has occurred. The rhythmic movements may produce some bodily injury via falls or muscle strains, but this is not reported in all patients. In unique cases, RMD sufferers hum or moan while asleep during an episode. Some patients describe the repetitive movements as relaxing and are only occasionally awakened by an RMD episode. Often, it is the sufferer’s partner or parent who first notes the symptoms. Additionally, it is often the partner or parent who led patients to seek medical attention.