Narcolepsy sleep disorder
Narcolepsy is one of the less common sleep disorders, yet one of the more life-disrupting ones. People with narcolepsy have difficulty staying awake during the day and tend to fall asleep without warning.
Strong emotional experiences, such as anger or surprise, may be accompanied by muscle weakness. Other possible symptoms may include a sense of paralysis or hallucinations when falling asleep or awakening.
The main characteristic of narcolepsy is excessive daytime sleepiness (EDS), even after adequate nighttime sleep. A person with narcolepsy is likely to become drowsy or fall asleep or just be very tired throughout the day, often at inappropriate times and places. Daytime naps may occur with little warning and may be physically irresistible. These naps can occur several times a day. They are typically refreshing, but only for a few hours. Drowsiness may persist for prolonged periods of time. In addition, nighttime sleep may be fragmented with frequent awakenings.
The classic symptoms of the disorder, often referred to as the "tetrad of narcolepsy," are cataplexy, sleep paralysis, hypnagogic hallucinations, and excessive daytime sleepiness. Other symptoms include automatic behaviors. These symptoms may not occur in all patients. Cataplexy is an episodic condition featuring loss of muscle function, ranging from slight weakness (such as limpness at the neck or knees, sagging facial muscles, or inability to speak clearly) to complete body collapse. Episodes may be triggered by sudden emotional reactions such as laughter, anger, surprise, or fear, and may last from a few seconds to several minutes. The person remains conscious throughout the episode. In some cases, cataplexy may resemble epileptic seizures. Sleep paralysis is the temporary inability to talk or move when waking (or less often, when falling asleep).