Narcolepsy is a rare neurological disorder that affects the brain’s ability to regulate normal sleepwake cycles. The term narcolepsy derives from the Greek νάρκη (narkē, "numbness" or "stupor"), and λῆψις (lepsis), "attack" or "seizure". It is a chronic disease most commonly affecting adolescents and young adults. It is characterized by daytime fatigue, sleep attack (falling asleep suddenly), temporary loss of control over the muscles in response to certain emotions (such as anger and laughter), and sleep paralysis, a temporary inability to move or talk when waking or falling asleep.
Narcolepsy is often caused due to a deficiency of orexin, a chemical in the brain that regulates sleep. However the exact cause of narcolepsy is not always clear. Hormonal changes during puberty and menopause, psychological stress, a sudden change in sleep cycles or an infection may trigger narcolepsy. To confirm a diagnosis of narcolepsy, your doctor may ask you to maintain a sleep log. Your levels of orexin may be measured, and tests such as polysomnography (measures body functions during sleep) and multiple sleep latency tests (measures brain activity during the day) may be ordered.
There is no cure for narcolepsy, patients with narcolepsy can be substantially helped, but not cured. Treatment is tailored to the individual, based on symptoms and therapeutic response. The time required to achieve optimal control of symptoms is highly variable, and may take several months or longer. Medication adjustments are frequently necessary, and complete control of symptoms is seldom possible. While oral medications are the mainstay of formal narcolepsy treatment, lifestyle changes are also important.