Narcolepsy

Pathophysiology
Narcolepsy is a rare, long-term brain disorder that causes a person to suddenly fall asleep at inappropriate times.The brain is unable to regulate sleeping and waking patterns normally, which can result in: 1.excessive daytime sleepiness – feeling very drowsy throughout the day, and having difficulty concentrating and staying awake 2.sleep attacks – falling asleep suddenly and without warning cataplexy  3.sleep paralysis.

Statistics
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.

Treatment
General sleep habits and avoidence of caffine contaning beverages will helps to ged rid of the problem. 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.