Variation of the motor activity profile according to sleep macro and microstructure in pediatric type 1 narcolepsy

Objectives/Introduction: Disrupted nighttime sleep (DNS) is a core symptom of type 1 narcolepsy (NT1), resulting from hypocretin neu- ronal loss. In this study we quantified the influence of DNS on NT1 children motor activity profile. Methods: Fifty-nine drug-naïve NT1 children and adolescents (age = 12.47 ± 3.56) underwent two weeks of actigraphy immedi- ately prior to the diagnostic hospitalization. The second PSG night was analyzed and the following variables extracted: percentage of N1, N2, SWS and REM sleep, SE and PLMi. For a subsamples of pa- tients (n = 47) we also computed sleep transitions index including: a) Wake index, b) NREM/2-3 to Wake/N1, c) REM/N2/N3 to Wake/ N1 and d) Wake/N1. Activity profiles were processed by mean of functional linear modeling (FLM) to convert and analyze raw activity in functional form. Results: The analysis show that the N1 sleep percentage has a sig- nificant influence on NT1 children's motor profile with higher per- centages of N1 sleep being associated with lower motor intensity between 12:00-14:00 (critical F < 0.05) and 18:00–20:00 (point- wise F < 0.05). Similarly, lower REM sleep percentage is associated with lower motor activity intensity between 11:00-13:00 (critical F < 0.05). On the contrary N2, SWS percentage and sleep transition index does not significantly influence the motor activity profile. Conclusions: These findings show that the N1 sleep percentage is linked to lower daytime activity levels. Combining information deriv- ing from actigraphy and PSG in a single analytical framework allows to characterize the effects of DNS on NT1 children's everyday life. Disclosure: Nothing to disclose.