Idiopathic Hypersomnia

Abstract

Idiopathic hypersomnia (IH) is a rare disease and essentially a diagnosis of exclusion. The age of onset varies but it is frequently present between the age of 10 and 30 years. The accurate diagnosis is difficulty and Careful history, physical examination, actigraphy, overnight polysomnogram (PSG) and mean sleep latency test (MSLT) or nap test is essential for diagnosis of IH. Also, it is important to rule out other causes of excessive daytime sleepiness. The key features of IH are excessive daytime sleepiness, PSG finding of high sleep efficiency, long sleep time and MSLT finding of decreased mean sleep latency and one or no sleep onset REM periods (SOREMs). IH causes significant psychosocial burden similar to narcolepsy. IH symptoms may be stable and long lasting but spontaneous remission may occur in up to one-third of the patients.