Sleep-related Rhythmic Movement Disorder (RMD) affects around 1% of UK pre-school children. Little is known about RMD in Down syndrome (DS). We aimed to determine: (a) the prevalence of RMD in children with DS aged 1.5-8 years; (b) phenotypic and sleep quality differences between children with DS and RMD and sex- and age-matched DS controls; and (c) night-to-night variability in rhythmic movements (RMs). Parents who previously reported RMs from a DS research registry of 202 children were contacted. If clinical history suggested RMD, home videosomnography (3 nights) was used to confirm RMs and actigraphy (5 nights) was used to assess sleep quality. Phenotype was explored by demographic, strengths and difficulties, Q-CHAT-10/social communication and life events questionnaires. Eight children had confirmed RMD. Minimal and estimated maximal prevalence were 4.10% and 15.38%, respectively. Sleep efficiency was significantly lower in RMD-cases (69.1%) versus controls (85.2%), but there were no other phenotypic differences. There was considerable intra-individual night-to-night variability in RMs. In conclusion, RMD has a high prevalence in children with DS, varies from night to night and is associated with poor sleep quality but, in this small sample, no daytime phenotypic differences were found compared to controls. Children with DS should be screened for RMD, which is amenable to treatment.

Jactatio corporis nocturna is a type of parasomnia. Rhythmic body movements during sleep are commonly observed in infancy and early childhood, and spontaneous resolution is expected after the age of 4 years. Rarely, the body movements persist until adulthood. Rhythmic body movements characteristically occur during the wake-sleep transition period, rather than during other sleep stages. Some psychiatric diseases can co-occur with sleep-related movement disorders. A relationship between parasomnias and dissociative disorders has been recently reported. Herein we present a 33-year-old male with nocturnal repetitive rolling body movements and daytime fatigue. The patient also had loss of memory of some important events (such as the day his daughter underwent surgery), and reported that he sometimes confused reality with dreams had fantasies during which he experienced his spirit rising above to watch his body and fantasy. Detailed neuropsychological assessment showed that the patient also had a dissociative disorder. Video-polysomnographic recordings showed repetitive, rolling body movements that occurred only during rapid eye movement (REM) sleep.

Sleep often terminates migraine headaches, and sleep disorders occur with greater prevalence in individuals with chronic or recurrent headaches. Rhythmic head, limb or body movements are common in children before falling asleep, but they very rarely persist into adolescence and adulthood, or appear de novo later in life as sleep-related rhythmic movement disorders. A 22-year-old female with migraine without aura and history of early childhood pre-dormital body rocking (jactatio) discovered that unilateral slow rhythmic movements of her right foot greatly facilitated falling sound asleep while reclining. Sleep served every time to terminate her migraine attack. Rhythmic movements may serve on occasion as a therapeutic hypnotic maneuver in migraine sufferers.

Rhythmic movement disorder, also known as jactatio capitis nocturna, is an infancy and childhood sleep-related disorder characterized by repetitive movements occurring immediately prior to sleep onset and sustained into light sleep. We report a 19-year-old man with a history of headbanging and repetitive bodyrocking since infancy, occurring on a daily basis at sleep onset. He was born a premature baby but psychomotor milestones were unremarkable. Physical and neurological diagnostic workups were unremarkable. A hospital-based sleep study showed: total sleep time: 178 min; sleep efficiency index 35.8; sleep latency 65 min; REM latency 189 min. There were no respiratory events and head movements occurred at 4/min during wakefulness, stages 1 and 2 NREM sleep. No tonic or phasic electromyographic abnormalities were recorded during REM sleep. A clinical diagnosis of rhythmic movement disorder was performed on the basis of the clinical and sleep studies data. Clonazepam (0.5 mg/day) and midazolam (15 mg/day) yielded no clinical improvement. Imipramine (10 mg/day) produced good clinical outcome. In summary, we report a RMD case with atypical clinical and therapeutical features.

Nocturnal rhythmic movements (jactatio capitis nocturnus, JCN) are very frequent in young children but persist only rarely in adults; studies including sleep recordings are exceptional in those cases. We report two new cases of young adults with JCN persisting since the first year of life, associated with restless sleep and diurnal sleepiness. Several episodes of JCN were recorded in each of the two patients; they always occurred after a period of paradoxical sleep, the waking phase preceding the rhythmic movements which are sometimes very short (1 s). The pathophysiology of adult JCN is discussed as a behavioral disorder of sleep onset conditioning or a disorder of sleep maintenance.

The case of a healthy 2-year-old girl with repeated nocturnal tongue biting as a result of rhythmic movements of the jaw associated with body rocking in non-REM sleep is described. Parasomnias manifesting with rhythmic, stereotyped movements of the head, trunk and extremities are well described in healthy children. The term rhythmic movement disorders (RMD) was introduced for these repetive movements in sleep which may appear as head banging (jactatio capitis), body rocking or leg rolling. Severe injuries including fractures, subdural effusions and eye injures are reported. Repeated tongue injuries have not been described as a consequence of RMD. The differential diagnosis from nocturnal seizures is crucial to avoid overtreatment of this benign albeit dramatically presenting condition.

Nocturnal head banging or body rocking often occurs in childhood in relation to sleep, and is generally considered a developmental or behavioral disorder. A few cases of jactatio nocturna have been considered manifestations of sleep disorder, and an analogy to somnambulism and pavor nocturnus has been suggested. We observed episodes of jactatio nocturna in a patient with global encephalopathy and frontal lobe dysfunction after closed head injury, and successfully treated these with imipramine. Sleep disorders are increasingly recognized after head injury; jactatio nocturna must be differentiated from post-traumatic seizures, and may represent partial or defective arousal during light non-REM sleep, analogous to the parasomnias of deeper sleep and possibly representing dysfunction of frontal arousal mechanisms.

A case of an adult female patient with jactatio capitis nocturnus evaluated in a sleep disorders center is reported. the unusual characteristics included symptoms initiating in early childhood and becoming more frequent with age, specifically observed during REM sleep. The occurrence in a 2-year-old son indicates the familial aspects of this syndrome.