Idiopathic hypersomnia

Idiopathic hypersomnia, which is probably one of the most frequently overdiagnosed sleep disorders, is not as well delineated and has a more recent history than narcolepsy. Two forms of the disorder have been described: polysymptomatic and monosymptomatic, the latter of which appears to be more heterogeneous. The most widely used polysomnographic procedure is nocturnal sleep recording followed by a multiple sleep latency test; however, continuous polysomnography, especially for the polysymptomatic form, is necessary to record the abnormally long major sleep episode and the long unrefreshing naps. Treatment of this disorder relies on stimulant medications. Modafinil, a new compound, may be effective in treating this condition.