Narcolepsy is a condition characterized by excessive sleepiness. A diagnosis of narcolepsy is based on a recurrent period of an irrepressible need to sleep, lapsing into sleep, or napping during the same day. These must have been occurring at least three times per week over the past 3 months.
In addition, a narcolepsy diagnosis requires at least one of the following:
- Episodes of cataplexy, defined as either (a) or (b), occurring at least a few times per month:
- a. Brief episodes of sudden loss of muscle tone preceded by laughter or joking.
- b. Spontaneous grimaces, or jaw-opening episodes with tongue thrusting, or decreased muscle tone, without any obvious emotional triggers.
- Nocturnal sleep polysomnography test results showing lower-than-normal levels of rapid eye movement (REM) sleep.
- Hypocretin deficiency, measured by inserting a needle into the spine (a test rarely used due to its dangers if something goes wrong).Hypocretin is a neuropeptide that transmits information between brain cells and plays a role in sleep regulation.
In addition to uncontrollable episodes of falling asleep during the day, other symptoms of narcolepsy include:
- Hallucinations that occur at sleep onset or upon awakening.
- Sleep paralysis, most often occurring when awakening in the morning.
Narcolepsy most frequently begins in adolescence or young adulthood, generally before the age of 30. The disorder either progresses slowly or reaches a plateau that is maintained throughout life.
What causes Narcolepsy?
Narcolepsy is caused by a basic central nervous system dysfunction of the brain involving the hypocretin system that regulates sleep and REM activity. Hypocretin is a neuropeptide that transmits information between brain cells and plays a role in sleep regulation.
What are treatments for Narcolepsy?
While no cure exists for narcolepsy, symptom management is possible. A regimen of forced naps at a regular time of day occasionally helps patients with narcolepsy. In some cases, this regimen alone can almost cure the condition without medication. When medication is required, stimulants are most commonly prescribed.
Sleep specialists often prescribe tricyclic drugs or SSRIs to reduce cataplexy. Although drug therapy is the treatment of choice, the overall therapeutic approach should include scheduled naps, lifestyle adjustment, psychological counseling, and drug holidays to reduce tolerance.