idiopathic hypersomnia

Idiopathic hypersomnia

Idiopathic hypersomnia (IH) is a neurological disorder which is characterized primarily by excessive sleep and excessive daytime sleepiness (EDS). Idiopathic hypersomnia was first described by Bedrich Roth in 1956, and it can be divided into two forms: polysymptomatic and monosymptomatic. The condition typically becomes evident in early adulthood and most patients diagnosed with IH will have had the disorder for many years prior to their diagnosis. As of August 2021, an FDA-approved medication exists for IH called Xywav, which is an oral solution of calcium, magnesium, potassium, and sodium oxybates; in addition to several off-label treatments (primarily FDA-approved narcolepsy medications). Idiopathic hypersomnia may also be referred to as IH, IHS, or primary hypersomnia, and belongs to a group of sleep disorders known as central hypersomnias, central disorders of hypersomnolence, or hypersomnia of brain origin. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) defines idiopathic hypersomnia as EDS without narcolepsy or the associated features of other sleep disorders. It occurs in the absence of medical problems or sleep disruptions, such as sleep apnea, that can cause secondary hypersomnia. It is relatively common for mood disorders (depression or bipolar disorder) to occur at the same time as IH, with a small increase in anxiety disorder diagnoses.