Narcolepsy type 1 features through the lifetime: age impact on clinical and polysomnographic phenotype

Objectives/Introduction: Narcolepsy type 1 (NT1) is a chronic neu- rological disorder typically arising during adolescence and young adulthood. Recent studies demonstrated that NT1 presents with age specific features, especially in children. With this study we aimed to describe and to compare the clinical pictures of NT1 in different ages groups. Methods: In this cross-sectional, multicentre study, 106 consecu- tive untreated NT1 patients were enrolled at the time of diagno- sis and underwent clinical evaluation, a semi structured interview (including the Epworth Sleepiness Scale – ESS), nocturnal video- polysomnography and the multiple sleep latency test (MSLT). Patients were divided into five age groups (childhood, adolescence, adulthood, middle-aged and seniors). Results: The ESS score showed a significant increase with age, while self-reported diurnal total sleep time was lower in elderlies and young adults, with the latter also complaining automatic behav- iors in more than 90% of cases. Children presented more frequent cataplexy attacks (>1/day in 95% of cases). ‘Recalling an emotional event’, ‘meeting someone unexpectedly’, ‘stress’ and ‘anger’ were triggers more frequently reported in adult and elderly patients. Neurophysiological data showed a higher number of SOREMPs at MSLT in adolescents compared to senior patients, and an age- progressive decline in sleep efficiency was observed. Conclusions: Daytime sleepiness, cataplexy features and triggers and nocturnal sleep structure showed age-related difference in NT1 patients; this variability may contribute to diagnostic delay and misdiagnosis. Disclosure: Nothing to disclose