title: Complex movement disorders at disease onset in childhood narcolepsy with cataplexy.
abstract: Narcolepsy with cataplexy is characterized by daytime sleepiness, cataplexy (sudden loss of bilateral muscle tone triggered by emotions), sleep paralysis, hypnagogic hallucinations and disturbed nocturnal sleep. Narcolepsy with cataplexy is most often associated with human leucocyte antigen-DQB1*0602 and is caused by the loss of hypocretin-producing neurons in the hypothalamus of likely autoimmune aetiology. Noting that children with narcolepsy often display complex abnormal motor behaviours close to disease onset that do not meet the classical definition of cataplexy, we systematically analysed motor features in 39 children with narcolepsy with cataplexy in comparison with 25 age- and sex-matched healthy controls. We found that patients with narcolepsy with cataplexy displayed a complex array of 'negative' (hypotonia) and 'active' (ranging from perioral movements to dyskinetic-dystonic movements or stereotypies) motor disturbances. 'Active' and 'negative' motor scores correlated positively with the presence of hypotonic features at neurological examination and negatively with disease duration, whereas 'negative' motor scores also correlated negatively with age at disease onset. These observations suggest that paediatric narcolepsy with cataplexy often co-occurs with a complex movement disorder at disease onset, a phenomenon that may vanish later in the course of the disease. Further studies are warranted to assess clinical course and whether the associated movement disorder is also caused by hypocretin deficiency or by additional neurochemical abnormalities.
authors.affiliation: Department of Neurological Sciences, University of Bologna, 40123 Bologna, Italy. giuseppe.plazzi@unibo.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Plazzi
authors.forename: Fabio
authors.initials: F
authors.lastname: Pizza
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Palaia
authors.forename: Christian
authors.initials: C
authors.lastname: Franceschini
authors.forename: Francesca
authors.initials: F
authors.lastname: Poli
authors.forename: Keivan K
authors.initials: KK
authors.lastname: Moghadam
authors.forename: Pietro
authors.initials: P
authors.lastname: Cortelli
authors.forename: Lino
authors.initials: L
authors.lastname: Nobili
authors.forename: Oliviero
authors.initials: O
authors.lastname: Bruni
authors.forename: Yves
authors.initials: Y
authors.lastname: Dauvilliers
authors.forename: Ling
authors.initials: L
authors.lastname: Lin
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Edwards
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Mignot
authors.forename: Kailash P
authors.initials: KP
authors.lastname: Bhatia
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D009069:Movement Disorders / Q000150:complications* / Q000503:physiopathology; D009290:Narcolepsy / Q000150:complications* / Q000503:physiopathology; D011446:Prospective Studies