[Hypersomnia--etiology, clinic, diagnosis and therapy of excessive sleepiness]

Hypersomnia (excessive sleepiness) refers to an increased sleep propensity with a subjective craving for sleep, involuntary naps and "sleep attacks" during the day and/or prolonged nighttime sleep with sleep drunkeness. Excessive sleepiness should be separated from fatigue and lack of energy associated with a variety of medical and psychiatric diseases. Hypersomnia is reported by 2-5% of the adult population and can lead to poor work, accidents and neuropsychiatric disturbances. Sleep apnea syndrome (SAS), narcolepsy, chronic sleep deprivation (insufficiency), and restless legs/periodic limb movements in sleep syndrome (RLS/PLMS) represent the most common causes of hypersomnia. The diagnosis of these conditions can often be suspected on clinical grounds. However, an overnight polysomnography and a multiple sleep latency test are often additionally required for definite diagnosis. Treatment options include nasal CPAP for SAS, stimulants for narcolepsy, sleep prolongation for sleep insufficiency, and dopaminergic agents for RLS/PLMS.