Preface

Sleepiness is a widespread condition in modern society, in part because sleep deprivation is so pervasive among adolescents and young adults, and increasing rates of obesity have led to sleep-related breathing disorders. However, many disorders that cause sleepiness are now recognized ranging from behavioral to medical, neurological and psychiatric causes. Sleepiness: Causes, Consequences and Treatment details the important pathophysiological and clinical features of most disorders of excessive sleepiness. The understanding of sleepiness in modern times is punctuated by a series of clinical, laboratory and therapeutic landmarks. Clinically, one of the first and most well-known descriptions was of Joe – the fat, sleepy boy who snored loudly; described in The Posthumous Papers of the Pickwick Club, by Charles Dickens in 1836. The condition of a 47-year-old male with “an irresistible and incessant propensity to sleep” was referred to as narcolepsy by Gelineau in 1880. Then Kleine, in 1925, described a 13-year-old boy who abruptly became drowsy after a febrile illness and displayed cognitive peculiarities for a period of 3 weeks with a similar episode 14 days later; a condition referred to in 1942 by Critchley and Hoffman as the Kleine–Levin syndrome. In 1923, von Economo described excessive sleepiness in patients with encephalitis lethargica that was associated with lesions in the tegmentum and posterior hypothalamus. In the 1950s, Roth described sleepiness, different from narcolepsy, that subsequently was called idiopathic hypersomnia.