Narcolepsy is a sleep disorder defined by constant sleepiness and a tendency to sleep at inappropriate times. Typically, a person with narcolepsy suffers sleep attacks as well as continual sleepiness and a feeling of tiredness that is not completely relieved by any amount of sleep. If not recognized and appropriately managed, narcolepsy can drastically and negatively affect the quality of a person's life.
There are Two Types of Narcolepsy
- Narcolepsy with cataplexy - This type of narcolepsy involves a combination of excessive daytime sleepiness and cataplexy. Cataplexy is when you have attacks that cause a sudden loss of muscle tone while you are awake. It may lead to slurred speech and buckling knees, or in more severe cases complete paralysis. These events are usually triggered by strong emotions such as joy, surprise, laughter or anger.
- Narcolepsy without cataplexy - This type of narcolepsy occurs when you have continuous excessive sleepiness but no cataplexy. You may take a nap for a couple of hours and wake up feeling refreshed. But after a short time, you feel tired again.
What Are the Symptoms of Narcolepsy?
When you add up the hours of total sleep time, people with narcolepsy don't necessarily sleep any more than people who don't have the sleep disorder. This is especially true when you consider that many people with narcolepsy often have difficulty sleeping through the night because of unwanted awakenings.
The four most common symptoms of narcolepsy are:
- Excessive daytime sleepiness
- Cataplexy
- Sleep paralysis
- Hypnagogic hallucinations
How is Narcolepsy Diagnosed?
The first step in diagnosing this disorder would be an evaluation from a sleep specialist. If your specialist suspects narcolepsy, you will be asked to undergo testing at the sleep center. There are two tests that are commonly performed, a polysomnogram (in-lab overnight study) and a multiple sleep latency test (MSLT), to confirm the diagnosis of narcolepsy and determine its severity.
During a Polysomnogram
During a polysomnogram you would spend the night at the sleep center in a designated sleep lab. Small electrodes are placed on your skin that record brain waves, muscle activity, heart rate, and eye movements, while other devices measure breathing. The procedure is painless, and is needed to determine whether you have other disorders that may be contributing to your symptoms.
Multiple Sleep Latency Test (MSLT)
A multiple sleep latency test is conducted the following day after a polysomnogram. With the electrodes still in place, you will be asked to take four to five 20-minute naps at two-hour intervals. The MSLT monitors how quickly you fall asleep and also your sleep pattern, since people with narcolepsy frequently have REM (dreaming) sleep even during a brief nap.
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