What causes narcolepsy?
Narcolepsy is a sleep disorder caused by a malfunction of the nervous system. It is widely considered to be the result of a deficiency of hypocretin, a chemical in the brain that activates arousal and regulates sleep. Why the deficiency occurs is unknown, but scientists are working on ways of supplementing hypocretin to reduce symptoms.
Narcolepsy is often inherited and symptoms include periods of extreme drowsiness every three to four hours, often resulting in a short nap. Most episodes last just 15 minutes, then they awake refreshed, but periods of sleep can last longer. It’s common for those afflicted to fall asleep after meals but it can also happen while driving, talking or at work. Sufferers may hallucinate at the stage between sleep and wakefulness, or experience sleep paralysis, where they are unable to move immediately before or after sleep. Further, during wakefulness, some people experience a sudden loss of muscle tone, called cataplexy.