Disorders Associated with Increased Sleepiness

Abstract

Sleepiness presents as increased likelihood of falling asleep during the day; however, in young children, behavioral problems such as irritability and impulsiveness can prevail. Consequence of excessive daytime sleepiness includes cognitive impairment accompanied by inattentiveness, academic difficulties, and mood changes. The most frequent causes of increased sleepiness are insufficient nocturnal sleep in obstructive sleep apnea, periodic leg movements, and restless legs syndrome (RLS). Alteration of circadian rhythms, predominantly sleep delay associated with chronic sleep loss, has a substantial role in increased daytime sleepiness in adolescence. The main topics of this chapter are disorders connected with central hypersomnolence. Narcolepsy type 1 is characterized by excessive daytime sleepiness and signs of REM-sleep dissociation, the most specific of which is cataplexy. It is connected with hypocretin deficiency in the cerebrospinal fluid. Narcolepsy type 2 has no cataplexy, and hypocretin level is usually normal. Childhood narcolepsy, particularly in young children, has some specific features. Sleep attacks may last several hours, and cataplexy may affect mainly muscles of the face. Idiopathic hypersomnia occurs rather rarely and starts usually in adolescence similarly to narcolepsy. Nocturnal sleep may be excessively long with difficult waking up and long-lasting daily naps. Multiple sleep latency test without sleep-onset REM periods (SOREMs) differentiates this disease from narcolepsy. Kleine-Levin syndrome is characterized by relapsing-remitting episodes of severe hypersomnolence, usually in association with cognitive, psychiatric, and behavioral disturbances. Secondary hypersomnolence includes cases due to medical disorders, such as brain injury, genetic disorders, and brain tumors, or due to psychiatric disorder or medication and other substance abuses. (PsycINFO Database Record (c) 2019 APA, all rights reserved)