Daytime continuous polysomnography in the diagnosis of pediatric narcolepsy type 1

Objectives/Introduction: Type 1 Narcolepsy (NT1) is still largely misdiagnosed or underdiagnosed in children also for difficulties to obtain a reliable diagnostic evaluation. NT1 fingerprints are sleep onset REM periods (SOREMPs) documented during nocturnal poly-somnography (nPSG) followed by the multiple sleep latency test (MSLT), cataplexy, and cerebrospinal hypocretin-1 (CSF hcrt-1) defi-ciency. Obtaining reliable MSLT results is not always possible, since it requires children's active collaboration and a dedicated setting. We aimed at validating daytime continuous polysomnography (D- PSG), an extension of the ambulatory EEG monitoring largely used in pedi-atric neurology, for NT1 diagnosis in children.Methods: Two hundred consecutive patients aged <18 years were included (112 with NT1, 25 with other central disorders of hyper-somnolence, and 63 with subjective sleepiness complaint). D- PSG findings from a 24-hours continuous PSG recording (number of naps (n-NAPs), total sleep time (D- TST), number of SOREMPs (D- SOREMPs)) were tested as single parameters and in combination against NT1 diagnosis by applying ROC curves analysis to extract cut-offs in a randomly selected group of 133 patients (group 1). Diagnostic testing performances indicators were calculated for vali-dation in the second group of 67 patients and in the whole dataset.Results: The presence of at least 1 D- SOREMPs (area of 0.913, S.E. 0.026, p = 6 E -16), at least 2 n-NAPs (area of 0.813, S.E. 0.038, p = 9 E- 10), and more than 60 minutes of D- TST (area of 0.695, S.E. 0.05, p = 0.0001) best identified NT1 patients as single parameters in group 1. Diagnostic odd ratios showed the best diagnostic performances for the combination of D- TST >60 min + at least 1 D- SOREMP (O.R. of 27.86 and of 49.05 in group 2 and in the whole dataset respec-tively), followed by the presence of at least 1 D- SOREMP (O.R. of 26.10 and of 44.33 in group 2 and in the whole dataset respectively).Conclusions: D- PSG recording is an ecological, easy to perform, cost-effective, and reliable tool for identifying NT1 children also outside of the sleep laboratory (i.e. by adopting home ambulatory monitoring) and for not collaborating patients. Disclosure: The authors did not have conflicts of interest related to the present work.