Narcolepsy is a chronic brain problem. Brain internal and external communications involve using chemicals to transmit messages. In narcolepsy, the messages that tells the body to completely relax, sleep and dream turn on and off abruptly at inappropriate times. Some patients, while walking will develop sudden onset of complete muscle relaxation and collapse to the floor. This is called cataplexy. Episodes can be triggered by intense emotions. Sometime patients will awaken in the morning with cataplexy and will be unable to move although they are aware of everything around them. This is called sleep paralysis. Others may be in the middle of a conversation and sudden fall asleep. This is called a sleep attack. Others may have sudden onset of vivid dreaming. The clarity of the dream recall may be quite intense and may provoke fear or may be perceived as a hallucination.
Victims: Narcolepsy is a genetic disorder and therefore runs in families. Teenaged boys are more commonly affected although it can occur in any sex and at any age.
Causes: Scientists at Stanford University, working with Dobermans, have observed sleep attacks and cataplexy, which is virtually identical to the narcolepsy, observed in humans. They have shown that these animals have brief sudden shift of brain activity to the REM state at inappropriate time. The observed phenomenon (sleep, dreaming and muscle relaxation or paralysis) is normal for the REM state. Therefore disregulation of REM seems to be the problem. REM is normally modulated by cholinergic and monoamine neurochemicals.
Diagnosis: The constellation of symptoms including excessive daytime sleepiness and cataplexy suggests the diagnosis of narcolepsy. Multiple sleep latency testing (MSLT), a technique, which measures brain electrical activity during multiple 20 minutes napping opportunities, is instrumental in confirming the diagnosis. People who are excessively sleep will fall asleep within ~8 minutes, while most normals will require >10 minutes. Most normal require ~90 minutes of sleep be for the onset of REM while patients with sleep deprivation or narcolepsy may have REM onset at the start of sleep.
Treatment: Therapy is individualized. If excessive daytime sleepiness is the predominant complaint, stimulating medications that interact with brain monoamines are used. These include Dexedrine, Ritalin and Cylert. Headaches, irritability, irregular heartbeat and mood changes may occur. Modafinil, a new class of alerting medication, is an option for those in which amphetamines may be inappropriate. If cataplexy is the primary problem, medications to suppress the REM state are employed. Antidepressants are the most commonly used agents for this. Gamma hydroxybutyrate is also effective in suppressing REM but may have profound negative effects on the cardiorespiratory system at high doses. In addition to medications, following good nocturnal sleep habits and utilizing planned naps during the day improves overall function.