Disease symptomatology and response to treatment in people with idiopathic hypersomnia: initial data from the Hypersomnia Foundation registry.

OBJECTIVE/BACKGROUND:Knowledge of idiopathic hypersomnia symptomatology derives from clinical case series. Web-based registries provide complementary information by allowing larger sample sizes, with greater geographic and social diversity. PATIENTS/METHODS:Data were obtained from the Hypersomnia Foundation's online registry. Common clinical features of idiopathic hypersomnia and other central disorders of hypersomnolence were queried, for the last thirty days and when symptoms were most severe. Symptoms were compared between idiopathic hypersomnia participants with and without long sleep durations and between participants with idiopathic hypersomnia and those with either form of narcolepsy. Frequency of medication use and residual symptoms on medication were evaluated. RESULTS:Five-hundred sixty-three registry respondents were included, with idiopathic hypersomnia (n = 468), narcolepsy type 2 (n = 44), and narcolepsy type 1 (n = 51). "Brain fog," poor memory, and sleep drunkenness were all present in most idiopathic hypersomnia respondents, with brain fog and sleep drunkenness more commonly endorsed by those with long sleep durations. Eighty-two percent of participants with idiopathic hypersomnia were currently treated with medication, most commonly traditional psychostimulants such as amphetamine salts. Among treated patients, symptoms improved while on medication, but substantial residual hypersomnia symptoms remained. Participants with narcolepsy type 1 were more likely than those with idiopathic hypersomnia to endorse intentional and unintentional daytime naps and automatic behaviors. CONCLUSIONS:Symptoms of idiopathic hypersomnia extend well beyond excessive daytime sleepiness, and these symptoms frequently persist despite treatment. These findings highlight the importance of online registries in identifying gaps in the use and effectiveness of current treatments.