RAPID WEIGHT GAIN AT DISEASE ONSET IN CHILDREN WITH NARCOLEPSY: A SPECIFIC INSIGHT IN PATHOPHYSIOLOGY?

Abstract

Introduction: Some authors have reported a rapid weight gain at the onset of the disease in narcoleptic children. The purpose of our study was to compare the clinical and electrophysiological characteristics of narcoleptic children with and without rapid weight gain. Methods: The data of 38 children (22 boys) followed in the Reference Center of Lyon were collected. All these children received the diagnosis of idiopathic narcolepsy after a complete clinical and electrophysiological evaluation. Rapid weight gain was defined by a change in weight percentile curve (+1SD) within the year of the first symptoms of the dis - ease. Patients were separated into children with rapid weight gain (type A) from those without any weight gain (type B) or with slow weight gain started more than one year before the clinical onset of the disease (type C). These data referred to new and non-treated children. Mann Withney rank and Fisher’s tests were used for statistical analysis. Results: Type A was more frequent (52.6%) than type B (21%) or type C (26.3%). The children with type A were younger (10.1± 3.8) than those with type B (13.1± 2.1 years) (p=.028) or type C (12.5±3.6). There was no obese in the type B. Although the % of obesity was not significantly different between type A (70%) and type C (100%), children with type A had lower sleep efficiency (p=.009), higher insomnia severity index (p= .004) and apnea-hypopnea index (p=.01), more WASO (p=.022), REM sleep (p=.024) during night and SOREM during MSLT (p=.027) than type C. The adapted Epworth score, the frequency of narcolepsy with cataplexy, of HLA-DQB1*0602 positive tended also to be higher in the type A. All the cases after H1N1 vaccine (n=3) have been found in this group. Conclusion: Narcoleptic children with weight gain at disease onset present specific characteristics that could be related to a rapid autoimmune process.