Idiopathic hypersomnia continues to evolve from the concept of "sleep drunkenness" introduced by Bedrich Roth in Prague in 1956 and the description of idiopathic hypersomnia with two forms, polysymptomatic and monosymptomatic, by the same Bedrich Roth in 1976. The diagnostic criteria of idiopathic hypersomnia have varied with the successive revisions of the International classifications of sleep disorders, including the recent 3rd edition. No epidemiological studies have been conducted so far. Disease onset occurs most often during adolescence or young adulthood. A familial background is often present but rigorous studies are still lacking. The key manifestation is hypersomnolence. It is often accompanied by sleep of long duration and debilitating sleep inertia. Polysomnography (PSG) followed by a multiple sleep latency test (MSLT) is mandatory, as well as a 24 h PSG or a 2-wk actigraphy in association with a sleep log to ensure a total 24-h sleep time longer than or equal to 66O minutes, when the mean sleep latency on the MSLT is longer than 8 min. Yet, MSLT is neither sensitive nor specific and the polysomnographic diagnostic criteria require continuous readjustment and biologic markers are still lacking. Idiopathic hypersomnia is most often a chronic condition though spontaneous remission may occur. The condition is disabling, sometimes even more so than narcolepsy type 1 or 2. Based on neurochemical, genetic and immunological analyses as well as on exploration of the homeostatic and circadian processes of sleep, various pathophysiological hypotheses have been proposed. Differential diagnosis involves a number of diseases and it is not yet clear whether idiopathic hypersomnia and narcolepsy type 2 are not the same condition. Until now, the treatment of idiopathic hypersomnia has mirrored that of the sleepiness of narcolepsy type 1 or 2. The first randomized, double-blind, placebo-controlled trials of modafinil have just been published, as well as a double-blind, placebo-controlled trial of clarithromycine, a negative allosteric modulator of the γ-aminobutyric acid-A receptor.

Department of Neurology 1st Faculty of Medicine Charles University Prague Katerinska 30 1200 Prague Czech Republic

Department of Neurology Gui de Chauliac Hospital 80 Avenue Augustin Fliche 34295 Montpellier Cedex 5 France

References provided by Crossref.org

Efficacy and Safety of Lower-Sodium Oxybate in an Open-Label Titration Period of a Phase 3 Clinical Study in Adults with Idiopathic Hypersomnia

Idiopathic Hypersomnia-A Dynamic Simulation Model

Data-Driven Phenotyping of Central Disorders of Hypersomnolence With Unsupervised Clustering

Idiopathic Hypersomnia: Historical Account, Critical Review of Current Tests and Criteria, Diagnostic Evaluation in the Absence of Biological Markers and Robust Electrophysiological Diagnostic Criteria