0941 Defining Disrupted Nighttime Sleep in Pediatric Narcolepsy

Abstract

Abstract Introduction Disrupted nighttime sleep (DNS) is a core narcolepsy symptom subjectively described as spontaneous awakenings during the night, but researchers use varied polysomnogram (PSG) definitions based on sleep state transitions, NREM 1% and poor sleep efficiency. These sleep measures have yet to be validated to determine the best objective measure of DNS. Furthermore, it unknown to what extent DNS occurs in pediatric narcolepsy as children have greater sleep drive than adults. Here, we assess the construct validity of various DNS objective measures and evaluate its diagnostic utility for pediatric Narcolepsy Type 1 (NT1) when combined with a nocturnal Sleep Onset REM period (nSOREMP) in a large cohort of pediatric patients with CNS hypersomnias. Methods Retrospective, cross-sectional study of consecutive PSGs and multiple sleep latency tests (MSLTs) obtained at Boston Children’s Hospital and University of Bologna. Participants were drug-free or drug naïve, ages 6-18 years and slept at least 6 hours during the PSG. We analyzed associations between objective DNS measures and outcomes of self-reported sleep disturbance, Epworth Sleepiness Score, mean sleep latency, NT1 diagnosis, and CSF hypocretin values when available. We then combined the best performing DNS measure with the presence of a nSOREMP to determine the diagnostic value for NT1 using bootstrap analysis. We included n=151 NT1, n=21 narcolepsy type 2 (NT2), n=27 idiopathic hypersomnia (IH) and n= 117 subjectively sleepy controls in this analysis. Results Across groups, the Wake and NREM 1 bouts index had the most robust associations with objective sleepiness, subjective sleep disturbance and CSF hypocretin levels (p’s <0.0001). From 1000 bootstrap samples, the Wake/N1 index and presence of a nSOREMP have greater diagnostic accuracy for NT1 than the nSOREMP alone (p<0.0001). Conclusion Among a variety of sleep quality measures, we find that a Wake and NREM 1 bout index is the best objective measure of DNS. In combination with a nSOREMP, this DNS measure can aid in pediatric NT1 diagnosis using PSG alone and potentially reduce diagnostic delays. Support This study was supported by K23 National Institutes of Health (NINDS, K23 NS104267-01A1) grant and Investigator Initiated Research grant from Jazz Pharmaceuticals, Inc. to Dr. Maski