144 Narcolepsy (347.00)
DSM-IV-TR criteria
A. Irresistible attacks of refreshing sleep that occurs daily over at least 3 months.
B. The presence of one or both of the following:
Cataplexy (brief episodes of sudden bilateral loss of muscle tone, which is most often associated with intense emotion.)
Recurrent intrusions of elements of rapid eye movement (REM) sleep into the transition between sleep and wakefulness, as manifested by either hypnopompic or hypnagogic hallucinations or sleep paralysis at the beginning of end of sleep episodes.
C. The disturbance is not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication) or another general medical condition.
Associated features
Narcolepsy is a neurological disorder in which the brain conveys sleep evoking signals at unexpected and inappropriate times. People with narcolepsy experience an inadequate order and length of NREM and REM sleep stages which are disrupted REM sleep episodes during sleep onset instead of after NREM sleep. During a time of excessive sleepiness, an individual with narcolepsy may temporarily experience muscle instability leading to paralysis or cataplexy of the head and body while the person remains awake and entirely conscious. Symptoms also include hypnagogic hallucinations, automatic behavior, insomnia and fragmented sleep associated with excessive day time sleepiness (EDS). Occurrences of narcolepsy may be prompted by sudden emotional reactions such as anger, surprise, fear, or even laughter. The episodes can last anywhere from several seconds to several minutes. Approximately forty percent of individuals with narcolepsy experience comorbidity with depression, anxiety, or substance-related abuse, and some may also experience all symptomatologies associated with narcolepsy.
Child vs. adult presentation
Narcolepsy can occur in children as young as five, but is more prominent during adolescence, though it is also possible for it to develop during young adulthood. Children with narcolepsy also suffer from excessive daytime drowsiness and cataplexy which is most often described as fainting in young children. Children frequently exert confusion and aggressive behaviors when woken up. Frequently, narcolepsy is misdiagnosed in children as a learning disability or attention deficit disorder. However, narcolepsy is usually more difficult to identify in children.
Gender and cultural differences in presentation
Narcolepsy is prevalent in relatively equal rates among males and females; however it has a genetic component that predisposes individuals to develop narcolepsy. Having a close relative that has narcolepsy increases an individual’s risk of developing the disorder by anywhere from twenty to forty times. There are very few variations in the severity and appearance of symptoms between different ethnic groups. Asians usually tend to report less severe incidents of negative emotions and hostility associated with narcolepsy, whereas Caucasian patien