Diagnosis and Treatment of the Central Disorders of Hypersomnolence

The central disorders of hypersomnolence (CDH) are lifelong conditions that cause an irrepressible need for sleep during waking hours. Some of these disorders are due to medications or other conditions, but narcolepsy type 1 (NT1), narcolepsy type 2 (NT2), and idiopathic hypersomnia (IH) occur as primary conditions. In each disorder excessive daytime sleepiness (EDS) may be accompanied by ancillary features such as sleep paralysis, hypnagogic/hypnopompic hallucinations, sleep drunkenness, or, in the case of NT1, cataplexy. Polysomnography and a multiple sleep latency test are used for diagnosis. Diagnostic lumbar puncture may be performed to differentiate NT1 from NT2. Although the mainstay of treatment for CDH is currently pharmacotherapy, management may also involve behavioral approaches such as sleep and nap scheduling, dietary modifications, and cognitive-behavioral therapy. Pharmacologic treatment can include traditional medications such as modafinil, methylphenidate, or sodium oxybate. Novel therapeutic agents such as pitolisant, clarithromycin, flumazenil, and melatonin may be useful in relieving EDS and associated symptoms.