Narcolepsy affects about 1 in 2,000 people. It is characterized by excessive sleepiness and abnormal intrusions of rapid eye movement (REM) or dream sleep phenomena into awake time.
Individuals with narcolepsy always exhibit excessive sleepiness and may or may not have some of the additional symptoms associated with narcolepsy.
Cataplexy and Other Associated Symptoms
One of the classic symptoms of narcolepsy is cataplexy. During REM sleep, our muscles are inactive (except for our muscles controlling our breathing and eye movements) and thus we are unable to move. In individuals with narcolepsy, this “paralysis” of muscles may occur during wakefulness and this is known as cataplexy. With cataplexy, the individual experiences a sudden onset of muscle weakness, usually brought on by strong emotions.
Muscle weakness or paralysis may also develop during transitions between sleep and wakefulness (known as sleep paralysis). In addition, dreams may intrude at these times (known as hypnagogic or hypnopompic hallucinations). Other symptoms of narcolepsy may include poor nighttime sleep with frequent awakenings and automatic behaviors (performing simple tasks without being aware of what you are doing or having recall of having done it).
While true cataplexy is considered very strong evidence of narcolepsy, the other symptoms listed are not specific to narcolepsy and may be seen in individuals who do not have narcolepsy. Furthermore, individuals diagnosed with narcolepsy may not have any or only some of these. Profound sleepiness, however, is always present. Generally, the sleepiness worsens over time and then eventually stabilizes, though some may experience a gradual improvement in their sleepiness with aging. However, all individuals with narcolepsy will have some degree of sleepiness for the duration of their lifetime. The other associated symptoms mentioned above also may vary over time, but many notice a gradual improvement with the passing of time.
The diagnosis of narcolepsy is usually determined by a sleep physician following a thorough history, examination, and objective testing. The testing to make the diagnosis typically requires a sleep study and a daytime nap study (known as a Multiple Sleep Latency Study).
The cause of narcolepsy is not completely clear, but recent data suggests some individuals with narcolepsy, especially those with cataplexy, may be lacking in certain brain chemicals (called hypocretinins or orexins) that function as an on/off switch between sleep and wakfulness. Why this happens and how this leads to the different symptoms of narcolepsy is not entirely known at this time, but ongoing research in this area may well provide some answers.
At present, narcolepsy cannot be cured, though it can be controlled. The available treatments focus on relief of symptoms and improving one’s quality of life. Simple maneuvers, such as practicing good sleep hygiene and taking regularly scheduled naps may help tremendously. Along these lines, it is important for those with narcolepsy to avoid situations that may worsen their symptoms – such as performing shift work, having a job that requires night-time calls, or any job that requires continuous attention for long periods of time without breaks. Individuals with a diagnosis of narcolepsy should also avoid safety sensitive occupations, such as commercial driving or operating construction equipment.
Specific treatment for narcolepsy is usually geared towards symptom relief. For the problem of excessive sleepiness, stimulant therapy is typically recommended. There are a variety of medications available for this and the appropriate medication is best determined after consultation with a Sleep Specialist. Treatment for cataplexy had been problematic in the past, with antidepressants being used with variable success. However, a medication known as, gamma hydroxy-butyrate (trade name of Xyrem®) has been FDA-approved specifically for the treatment of cataplexy and is quite effective at relieving this symptom.
More Articles About Sleep:
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- Common Sense Tips for Good Sleep
- Jet Lag
- Keeping Time with Your Internal Clock – Circadian Rhythms
- Restless Legs Syndrome
- Sleep Tips for Shift Workers
- The Secret to Slimming Down for Summer: Get Your Zzzs!
For more information:
Go to the Sleep Disorders health topic.