Idiopathic Hypersomnia with Long Sleep Time

Idiopathic hypersomnia with long sleep time is a very rare disorder. It is characterized by chronic excessive daytime sleepiness and prolonged nocturnal sleep periods. Severe sleep inertia, both after nocturnal and daytime sleep, is experienced by a majority of patients. Daytime naps are typically long and not refreshing. The onset of the disorder is insidious and tends to occur during adolescence and early adulthood. Although rare spontaneous improvements have been reported, in general, idiopathic hypersomnia is a chronic, disabling condition associated with significantly reduced quality of life. The pathophysiology of idiopathic hypersomnia with long sleep time is currently unknown.