Narcolepsy is a somewhat rare, but fairly well known, chronic sleep disorder that affects an estimated three million people worldwide. Individuals with narcolepsy experience extreme daytime fatigue and fall asleep at inappropriate times during daily activities, such as working or even while eating. Although many people with narcolepsy feel an extreme urge to fall asleep at irregular hours, for some individuals, it is practically unavoidable.
Drowsiness and daytime sleeping, even after one has had enough rest the night before, are the most common symptoms of narcolepsy, but other symptoms are prevalent in many cases of this disorder. Cataplexy, or a sudden loss of muscle tone, is one such symptom that sometimes may be brought about by a person experiencing a strong emotional trigger. In most cases, cataplexy may result in the momentary loss of facial muscle tone or a feeling of weakness in the knees, but can also result in a person collapsing to the ground.
Narcolepsy can often be characterized by automatic behaviors, which are unconscious and uncontrollable like speaking without purpose or sitting up and looking around a room while actually asleep. Another common symptom more closely related to sleeping is hypnagogic hallucinations, which are the result of a person awakening during REM sleep, while the brain is still inhibiting muscle movement in the body. Sleep paralysis is another side effect that refers to a person suddenly being unable to move or speak while awake; this is similar to a waking version of the muscle inhibition experienced during REM sleep.
The symptoms of excessive sleepiness, inappropriate sleeping, cataplexy, hypnagogic hallucinations, automatic behavior and sleep paralysis are usually the diagnostic criteria used when trying to determine if a patient has narcolepsy. Although a person may sometimes experience insomnia as part of his or her symptoms, this usually occurs only for shorter periods of time and is followed by a longer span of daytime fatigue. In cases where the fatigue is relatively minor or where cataplexy does not occur, narcolepsy is harder, but still possible, to diagnose.
In these cases, a sleep specialist will usually use a polysomnogram that reads brain waves to look for the traits of falling asleep quickly, entering REM sleep almost immediately and episodes of waking up often during the night. Additionally, a multiple sleep latency test may be used in order to see at what times a person enters the different sleep stages, which accounts for the symptom of entering REM sleep more quickly than normal.
Narcolepsy is managed using a number of treatments. Stimulants, such as amphetamines, may be used to cover up the symptoms of daytime sleepiness and prevent inappropriate sleeping, but these do not treat the causes of narcolepsy. To more directly treat physical causes, tricyclic antidepressants or the drug gamma-hydroxybutyrate may be used. Psychological approaches usually involve training a person with narcolepsy to take planned naps on a regular basis, reducing stress, exercising often or even changing professions to a night job, where sleep attacks may occur less often.
