Clinical considerations for the diagnosis of idiopathic hypersomnia

Idiopathic hypersomnia is a sleep disorder of neurologic origin characterized by excessive daytime sleepiness, with sleep inertia, long, unrefreshing naps, and prolonged nighttime sleep being key symptoms in many patients. Idiopathic hypersomnia is described in the International Classification of Sleep Disorders, 3rd Edition as a central disorder of hypersomnolence with distinct clinical features and diagnostic criteria; however, confirming the diagnosis of idiopathic hypersomnia is often challenging. Diagnosis of idiopathic hypersomnia is based on objective sleep testing and the presence of associated clinical features but may be difficult for clinicians to recognize and correctly diagnose because of its low prevalence, clinical heterogeneity, and symptoms, which are similar to those of other sleep disorders. The testing required for diagnosis of idiopathic hypersomnia also presents logistical barriers, and reliability of objective sleep measures is suboptimal. The pathophysiology of idiopathic hypersomnia remains unknown. In this review, clinical considerations related to the pathogenesis, diagnosis, and management of idiopathic hypersomnia will be discussed, including perspectives from the European Union and United States.