Narcolepsy is a neurological disorder caused by the brain's inability to regulate sleep-wake cycles normally. The main features of narcolepsy are fatigue and cataplexy. The disease is also often associated with sudden sleep attacks, insomnia, dream-like hallucinations, and a condition called sleep paralysis. Symptoms include Excessive daytime sleepiness Cataplexy - is a sudden loss of muscle tone Hypnogogic hallucinations Sleep paralysis.
Emotion-induced laughter occurred in 16 patients, and of these 10 showed cataplexy for a total of 77 events (mean duration = 4.4 s). Cataplexy was marked by brief losses of mylohyoid muscle tone and by the observation of episodes of facial hypotonia, jaw drop, and ptosis. During laughter an increased hemodynamic response occurred in a bilateral network involving the motor/premotor cortex and anterior cingulate gyrus.
Severe daytime sleepiness may require treatment with high doses of stimulant medication, and sometimes a combination of stimulants may be needed. Rare or infrequent cataplexy and other associated symptoms may not require any drug treatment, or treatment on an "as needed" regimen may be adequate.