Narcolepsy is a neurological disorder caused by the brain's inability to regulate sleep-wake cycles. It is a disorder in which a person falls asleep at inappropriate times. People with narcolepsy generally experience disturbed nocturnal sleep and an abnormal daytime sleep pattern, which is often confused with insomnia.
Narcoleptics, when falling asleep, generally experience the REM (Rapid Eye Movement) stage of sleep within 5 minutes, while most people without narcolepsy may not experience REM sleep until an hour. REM sleep is where most dreams occur.
Excessive Daytime Sleepiness:
The main characteristic of narcolepsy is Excessive Daytime Sleepiness (EDS) in which even after adequate night time sleep. A person becomes drowsy or fall asleep or just be very tired throughout the day, often at inappropriate times and places.
Cataplexy i.e. a sudden muscular weakness brought on by strong emotions (though many people experience cataplexy without having an emotional trigger) . It often manifests as muscular weakness ranging from a bare slackening of the facial muscles to the dropping of the jaw or head, feeling weak at the knees (often referred to as "knee buckling "), or a total collapse.
Narcolepsy is known to be caused by an autoimmune response.
In 2010, scientists in Switzerland discovered that the reduction of chemical (hypocretin) in brain is caused by an autoimmune response to an antibody called trib 2. The trib 2 antibodies attack the areas of the brain that produce orexin. The attack leads to a deficiency in orexin, which results in narcolepsy and, in particular, narcolepsy with cataplexy (temporary muscle weakness).
Diagnosis is relatively easy when all the symptoms of narcolepsy are present, but if the sleep attacks are isolated and cataplexy is mild or absent, diagnosis is more difficult. It is also possible for cataplexy to occur in isolation . Three tests that are commonly used in diagnosing narcolepsy are:
The polysomnogram involves continuous recording of sleep brain waves and a number of nerve and muscle functions during nighttime sleep. When tested, people with narcolepsy fall asleep rapidly, enter REM sleep early, and may awaken often during the night. The polysomnogram also helps to detect other possible sleep disorders that could cause daytime sleepiness.
Multiple Sleep Latency Test (MSLT):
For the Multiple sleep latency test, a person is given a chance to sleep every 2 hours during normal waking time. The patient is usually subjected to an overnight sleep study.
Epworth Sleepiness Scale:
The Epworth sleepiness scale is a brief questionnaire that is administered to determine the likelihood of the presence of a sleep disorder, including narcolepsy These tests are usually performed by a sleep specialist.
There is no specific cure of the disease. One of the best ways to manage excessive daytime sleepiness is to take frequent, brief naps evenly spaced through the day.