Narcolepsy is a chronic neurological disorder of the central nervous system characterized by the brain's inability to control sleep cycles. Researchers believe that narcolepsy may be due to a deficiency in the production of a chemical called hypocretin by the brain. People with narcolepsy experience episodes of uncontrollable sleep during daytime activities. The onset of sleep is sudden and can last from a few seconds to several minutes. A narcoleptic episode can occur at anytime, making driving and operating machine very dangerous.
Symptoms of narcolepsy include uncontrollable bouts of sleep, daytime sleepiness, cataplexy (sudden loss of voluntary muscle tone and control), hallucinations during sleep, and temporary paralysis during onset of sleep or waking.
Three tests are used to diagnose narcolepsy and are conducted in a sleep lab with appropriate prescription from your doctor. The tests include the polysomnogram, the Multiple Sleep Latency Test (MSLT), and the Epworth Sleepiness Scale.