The term narcolepsy derives from the French word narcolepsie created by the French physician Jean-Baptiste-Édouard Gélineau by combining the Greek νάρκη (narkē, "numbness" or "stupor"), and λῆψις (lepsis), "attack" or "seizure".

Narcolepsy is a chronic sleep disorder, or dyssomnia, characterized by excessive sleepiness and sleep attacks at inappropriate times, such as while at work. People with narcolepsy often experience disturbed nocturnal sleep and an abnormal daytime sleep pattern, which often is confused with insomnia. Narcoleptics, when falling asleep, generally experience the REM stage of sleep within 5 minutes; whereas most people do not experience REM sleep until an hour or so later.

Another one of the many problems that some narcoleptics experience is cataplexy, a sudden muscular weakness brought on by strong emotions (though many people experience cataplexy without having an emotional trigger). It often manifests as muscular weaknesses ranging from a barely perceptible slackening of the facial muscles to the dropping of the jaw or head, weakness at the knees (often referred to as "knee buckling"), or a total collapse. Usually speech is slurred and vision is impaired (double vision, inability to focus), but hearing and awareness remain normal. In some rare cases, an individual's body becomes paralyzed and muscles become stiff. Some narcolepsy affected persons also experience heightened senses of taste and smell.

Narcolepsy is a neurological sleep disorder. It is not caused by mental illness or psychological problems. It is most likely affected by a number of genetic mutations and abnormalities that affect specific biologic factors in the brain, combinedwith an environmental trigger during the brain's development, such as a virus.

Narcolepsy, Idiopathic and Recurrent hypersomnia

Hypersomnias of central origin are recognized within the international classification of sleep disorders and includes:
» Narcolepsy with and without cataplexy
» Idiopathic hypersomnia
» Recurrent Hypersomnia.

This is a medical condition associated with excessive daytime sleepiness, hypnagogic hallucinations, sleep paralysis, cataplexy and poor night time sleep.
The incidence of narcolepsy is 0.2-1/1000 individuals. The first signs of narcolepsy (excessive daytime sleepiness) usually manifest in adolescence but are frequently unrecognized. Most patients are diagnosed as adults when cataplexy (sudden loss of voluntary muscle tone) occurs.

The classic tetrad of symptoms include:
» Excessive daytime sleepiness:
Typically the patient complains of increased daytime sleepiness. In children this is typically ignored or considered secondary to poor sleep habits.

» Hypnagogic hallucinations:
This is a condition in which the patient relates a history of having episodes wherein the patient goes to sleep, and promptly goes into a dream state, wakes up abruptly and has difficulty differentiating between wakefulness and dream events.

» Sleep paralysis:
In this condition, the patient has episodes in which they awake from sleep and are unable to move. The sensation typically only lasts a few seconds.

» Cataplexy:
This is a condition in which the patient has a sudden loss of muscle tone. It is typically associated with a strong emotional event (laughter, anger, happiness, extreme sadness). There is no loss of consciousness.

» A fifth manifestation is poor night time sleep:
Patients with narcolepsy tend to report fragmented and poor night time sleep which runs counter to the fact that they have excessive daytime sleepiness
Several teenage patients with narcolepsy have mood disorders, mostly depression at the time of diagnosis. Occasionally patients are diagnosed following negative evaluations by cardiology and neurology for suspected seizures and near syncopal events.

» Evaluation:
Patients require an evaluation by a sleep specialist and this should include a full history and physical examination, completion of a subjective sleepiness scale (Epworth sleepiness scale), maintenance of sleep logs, and performance of an overnight sleep study and a multiple sleep latency test.

» Treatment:
Excessive daytime sleepiness
Behavioral and Medical management

» Behavioral: Improved sleep hygiene, addition of a daytime nap

» Medical:
» Somnolytic agents:
Modafinil (Provigil), Armodafinil (Nuvigil)

» Psychostimulants: Amphetmine-Dextroamphetamine salts (Adderall, Adderall XR), Methylphenidate (Ritalin).

» Cataplexy management:
Sodium Oxybate (Xyrem)

» SSRI’s: Sertraline (Zoloft), Fluoxetine (Prozac)
» SNRI’s: Venlafaxine (Effexor)
» TCA’s: Clomipramine (Anafranil), Protriptyline (Vivactil)