Hypersomnolence Disorders

Abstract

Despite varied classification systems, hypersomnolence disorders (or central disorders of hypersomnolence) are a group of disorders with a common symptom of excessive daytime sleepiness. In addition to a thorough clinical interview and examination, the assessment of hypersomnolence may require clinical investigations such as polysomnography and the multiple sleep latency test. This chapter examines the disorders of hypersomnolence with an emphasis on their clinical features and treatment strategies. The authors discuss the four main types of hypersomnolence disorders, narcolepsy type 1, narcolepsy type 2, idiopathic hypersomnia and Kleine–Levin syndrome, as well as hypersomnia due to a medical disorder, medication, or substance use; a psychiatric disorder; and insufficient sleep syndrome. It also discusses the relationships between hypersomnolence and psychiatric disorders.