Idiopathic hypersomnia symptoms over Time: Longitudinal follow up from the Hypersomnia Foundation registry

Introduction: Limited data are available regarding the long-term course of idiopathic hypersomnia. We analyzed longitudinal data from the Hypersomnia Foundation Registry at CoRDS to evaluate changes in symptoms and medication usage over time. Methods: Registry participants reporting a diagnosis of idiopathic hypersomnia were included if they completed the registry questionnaire at least twice, with at least six months before first and last questionnaire. Responses were analyzed using paired t-test for continuous variables and McNemar test for categorical variables, comparing first and last responses. Results: Data from three hundred twenty-three participants were included, with a mean age 35.0 +/- 12.2 and 86.5 % women. Average time between first and last response was 2.4 +/- 1.4 years. Symptoms remained largely stable over the 2 1/2 year period, with persistent difficulty awakening (in 78.7 % at baseline and 73.0 % at follow up), daytime sleepiness (62.7 % and 61.8 %), trouble waking up and functioning with normal alertness (56.4 % and 56.4 %), requiring multiple alarms (53.4 % and 55.3 %), brain fog (46.3 % and 48.4 %), and memory problems (42.7 % and 43.4 %). Average nightly sleep duration on workdays and non-workdays and average nap duration were all stable over time. Participants made an average of 0.8 ( +/- 1.1) medication changes, with most (55.4 %) participants remaining on the same medications. Comorbid mood disorders were relatively common, with a modest increase in anxiety diagnoses. Conclusions: Symptoms of idiopathic hypersomnia remained relatively stable over an average of 2.4 years of follow up. Despite persistent symptoms being experienced by the majority of participants, medication changes were infrequent.