What're the symptoms of narcolepsy?
The earliest symptom of narcolepsy is usually daytime sleepiness, which may be extreme. However, it may take years to recognize the disorder because other, more common causes of daytime sleepiness often are blamed for the symptoms. Excessive daytime sleepiness occurs every day, regardless of the amount of sleep obtained at night. EDS is usually experienced as a heightened sensitivity (sometimes an almost irresistible susceptibility) to becoming sleepy or falling
asleep, especially in sleep-inducing situations. Patients describe the problem as sleepiness, tiredness, lack of energy, exhaustion, or a combination of these feelings, either continuously or at various times throughout the day.
Sometimes sleepiness occurs so suddenly and with such overwhelming power that it is referred to as a "sleep attack." Some patients have several "attacks" each day. When the attack occurs during the day, sleep usually lasts for less than 30 minutes, but sometimes the patient stays asleep for several hours. Paradoxically, persons with narcolepsy who suffer from significant daytime sleepiness often describe poor quality, interrupted sleep at night. Many complain of difficulty in memory. Some describe automatic behavior, reporting that they have been told that they have performed inappropriate acts that they cannot remember. Occasionally there will be introductions of blurred vision or diplopia.
Cataplexy is an abrupt loss of voluntary muscle tone, usually triggered by emotional arousal. Attacks can range in severity from a brief sensation of weakness to total collapse lasting several minutes. Cataplexy can cause a range of physical changes, from slurred speech to total physical collapse, and may last for a few seconds to a few minutes. Cataplexy is uncontrollable and is often triggered by intense emotions, such as laughter, fear, surprise or anger, or sometimes by strenuous activity. For example, your head may droop uncontrollably when you laugh or your knees may suddenly buckle while you're working out. Some people with narcolepsy experience only one or two episodes of cataplexy a year, while others have numerous episodes each day. About 70 percent of people with narcolepsy experience cataplexy.
Hallucinations are intense, vivid, sometimes accompanied by frightening auditory, visual, and tactile sensations, and occur just on awakening or falling asleep. Sleep paralysis is the temporary inability to move while falling asleep or awakening. It lasts no more than several minutes. Like cataplexy, sleep paralysis probably is related to insufficient separation between REM sleep and the awake state. Both sleep paralysis and hypnagogic/hypnopompic hallucinations are also associated with the intrusion of REM sleep physiology into wakefulness. Occasionally, they are extremely difficult to distinguish from reality.
The symptoms of narcolepsy are usually first noticed during the teenage or young adult years although it can strike at any age. Most often the initial symptom to appear is excessive daytime sleepiness. Later, after several months or even years, cataplexy or one or more of the other symptoms frequently develops. Different individuals experience wide variations in the development, number, and severity of their symptoms. Family, friends, educators, employers, and even those with narcolepsy often have a hard time understanding the problem and just what is happening.