symptom
The signs and symptoms of narcolepsy may worsen in the first few years and then persist throughout life. They include:
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Excessive daytime sleepiness. People with narcolepsy can fall asleep anytime and anywhere without warning. For example, you might be working or talking to friends and then suddenly doze off, lasting anywhere from a few minutes to half an hour. When you wake up, you'll feel refreshed, but eventually you'll drift back to sleep.
You may also experience decreased alertness and concentration throughout the day. Excessive daytime sleepiness is often the first and most troublesome symptom, making it difficult to concentrate and function fully.
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Sudden loss of muscle tone. This condition, called cataplexy, can cause many physical changes, from slurred speech to complete weakness of most muscles, and can last for up to several minutes.
Cataplexy is uncontrollable and is triggered by strong emotions, usually positive emotions such as laughter or excitement, but sometimes fear, surprise, or anger. For example, when you laugh, your head may drop uncontrollably, or your knees may buckle suddenly.
Some people with narcolepsy experience only one or two episodes of cataplexy a year, while others have multiple episodes per day. Not everyone with narcolepsy develops cataplexy.
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Sleep paralysis. People with narcolepsy are often temporarily unable to move or speak when falling asleep or waking up. These episodes are often short—lasting seconds or minutes—but can also be frightening. Even if you have no control over what happens to you, you may be aware of the situation and have no difficulty recalling it afterwards.
This type of sleep paralysis mimics the type of temporary paralysis that typically occurs during a period of sleep called rapid eye movement (REM) sleep. This temporary immobility during REM sleep may prevent your body from engaging in dream activity.
However, not everyone with sleep paralysis has narcolepsy. Many people without narcolepsy experience some episodes of sleep paralysis.
- Changes in rapid eye movement (REM) sleep. REM sleep is usually when most dreaming occurs. People with narcolepsy can have REM sleep at any time of the day. People with narcolepsy typically transition rapidly to REM sleep within 15 minutes of falling asleep.
- hallucination. These hallucinations are called hypnagogic hallucinations if they occur while you are asleep, or hypnagogic hallucinations if they occur when you are awake. An example is feeling as if there is a stranger in your bedroom. These hallucinations can be particularly vivid and frightening because you may not be fully asleep when you start to dream and you experience the dream as reality.
Other features
People with narcolepsy may have other sleep disorders, such as obstructive sleep apnea (a condition in which breathing starts and stops throughout the night), restless legs syndrome, or even insomnia.
Some people with narcolepsy experience automatic behaviors during brief narcolepsy episodes. For example, you may fall asleep while performing a task you normally perform (such as writing, typing, or driving) and continue performing that task while you fall asleep. When you wake up and you don't remember what you did, you probably didn't do it well.
when to see the doctor
If you experience excessive daytime sleepiness that disrupts your personal or professional life, see your doctor.
reason
The exact cause of narcolepsy is unknown. People with narcolepsy type 1 have lower levels of the chemical hypocretin. Orexin (Hypocretin) is an important neurochemical in the brain that helps regulate wakefulness and REM sleep.
People with cataplexy have particularly low levels of hypocretin. The exact cause of the loss of cells in the brain that create the hypothalamus is unknown, but experts suspect it is due to an autoimmune response.
Genetics may also play a role in the development of narcolepsy. But the risk of parents passing the disease on to their children is very low — only about 1 percent.
Research also suggests it may be related to exposure to the swine flu (H1N1 flu) virus and some form of the H1N1 vaccine currently in use in Europe, but the cause is currently unclear.
Normal sleep patterns and narcolepsy
The normal process of falling asleep begins with a stage called non-rapid eye movement (NREM) sleep. During this stage, your brain waves slow down significantly. After an hour or so of NREM sleep, your brain activity changes and REM sleep begins. Most dreaming occurs during REM sleep.
However, in narcolepsy, you may suddenly enter REM sleep without first experiencing NREM sleep, either at night or during the day. Some features of narcolepsy—such as cataplexy, sleep paralysis, and hallucinations—are similar to the changes that occur in REM sleep, but occur during periods of wakefulness or drowsiness.
risk factors
There are only a few known risk factors for narcolepsy, including:
- age. Narcolepsy usually begins in people between the ages of 10 and 30.
- family history. If you have a family member with narcolepsy, your risk of developing narcolepsy is 20 to 40 times greater.
complication
- Public misunderstanding of the condition. Narcolepsy can cause serious problems for you professionally and personally. Others may think you are lazy or lethargic. Your performance at school or work may be affected.
- Interference in intimate relationships. Intense emotions, such as anger or joy, can trigger signs of narcolepsy, such as cataplexy, causing the affected person to withdraw from emotional interactions.
- Bodily harm. Sleep attacks can cause physical harm to people with narcolepsy. If you are assaulted while driving, you are at increased risk of being involved in a car accident. If you fall asleep while preparing food, you are at greater risk of cuts and burns.
- obesity. People with narcolepsy are more likely to be overweight. Weight gain may be related to low metabolism.
cure
While there is no cure, some lifestyle changes and medications may help. Lifestyle changes include taking regular naps and maintaining sleep hygiene.
Medications used include modafinil, sodium oxybate, and methylphenidate. While initially effective, tolerance to the benefits may build up over time. Tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRIs) can improve cataplexy.
