Narcolepsy and Idiopathic Daytime Hypersomnia: A Study of Cohort in the Chilean Population

Introduction: Central disorders with hypersomnolence (CDH) are a group of sleep disorders characterized by excessive daytime sleepiness (EDS) that can be related to REM-sleep dissociative symptoms. They have a low prevalence in the population and may not be explained by other medical conditions. Materials and methods: A cohort of 59 Chilean patients with the most common types of CDH were studied. Clinical data, and results of polysomnography (PSG) plus multiple sleep latency tests (MSLT) were analyzed.. Results: The median age of the cohort was 35.26 ± 13.23 years (69.5% female). Diagnosis of narcolepsy Type 1, narcolepsy Type 2, and idiopathic daytime hypersomnia, were determined in 54.2%, 23.7% and 22% of patients respectively. All patients reported EDS, while 57.6%, 81.4% and 78% reported cataplexy, sleep paralysis and hypnagogic/hypnopompic hallucinations respectively. Polysomnographic studies showed non relevant alterations in the majority of patients. The MLTS was abnormal in all patients, 78% of them with 2 or more sleep onset REM periods (SOREMP). In 52.5% of cases, the delay in final diagnosis was more than 5 years. About a third of patients had another sleep disorder that could not explain the severity of EDS. We observed a comorbidity with an immunological disorder in 30.5% of patients. Conclusion: The EDS is the main symptom in CDH. Related REM-sleep symptoms and MSLT alterations were the second most important features to establish final diagnosis. However, we observed a significant delay in CDH diagnosis in the majority of patients.