Narcolepsy is a disorder of the nervous system that causes drowsiness and sleep attacks. It’s also known as daytime sleep disorder, or cataplexy. Narcolepsy isn’t a deadly disease, but accidents that occur during an episode can cause injuries or be life-threatening.
The symptoms of narcolepsy usually begin between the ages of 10 and 25, and the people who develop the condition earlier than others tend to have more severe symptoms. Most people with narcolepsy are undiagnosed and untreated.
The symptoms of narcolepsy are related to the processes of rapid eye movement (REM) sleep. These include a recurrent and irrepressible need to sleep, a lapse into sleep, and napping occurring within the same day. These symptoms must occur at least three times per week for at least three months. The person may report experiencing dreaming, decreased consciousness, and muscle paralysis.
Excessive daytime drowsiness is usually the first symptom of narcolepsy. It makes it difficult to function properly on the job and elsewhere.
A sudden, temporary loss of muscle tone, also known as cataplexy, can be triggered by intense emotions. These may include:
The frequency of cataplexy varies. Some people have it several times per day. Other people experience it a few times per year.
Hallucinations can also occur in people with narcolepsy. This is because dreaming is part of REM sleep. If dreams occur when you’re partially awake, they may seem like reality.
Sleep paralysis is an inability to move or speak while falling asleep or waking. Episodes last only a few minutes. Out of all people with narcolepsy, young adults are most likely to experience sleep paralysis. Sleep paralysis mimics the paralysis seen during REM sleep and can even occur in people who don’t have narcolepsy.
Narcolepsy is also associated with other disorders such as obstructive sleep apnea, restless legs syndrome, and insomnia.
The cause of narcolepsy is unknown. However, people with it have a decreased amount of a brain protein called hypocretin. Hypocretin helps regulate your cycles of wakefulness and REM sleep.
Some scientists think low hypocretin levels may be caused by an autoimmune response. In autoimmune diseases, the immune system attacks healthy cells. Other factors such as stress, exposure to toxins, and infection also may play a role in narcolepsy.
Sleep occurs in stages. At the beginning of the sleep process, brain waves slow down. This is when non-rapid eye movement (NREM) sleep occurs. After 90 minutes to two hours, REM sleep begins. In REM sleep, brain waves increase. Dreaming and muscle paralysis occur during REM sleep.
People with narcolepsy can suddenly fall asleep, lose muscle tone, and begin to dream. This may happen no matter what they’re doing or what time of day it is. When this happens, their REM sleep occurs spontaneously and they skip NREM sleep. The symptoms of REM sleep happen all at once.
The Center for Narcolepsy at the Stanford University School of Medicine reports that one in every 2,000 Americans has narcolepsy. Your doctor will ask you about your medical history and perform a physical exam. They’ll look for a history of excessive daytime drowsiness and episodes of sudden loss of muscle tone. Formal diagnosis may require a sleep study and several tests may be needed to diagnose your narcolepsy.
Some of these tests include the following:
- The Epworth sleepiness scale (ESS) is a simple questionnaire. It asks how likely you are to sleep in different circumstances.
- ActiGraph monitoring keeps track of how and when you fall asleep. This device is worn like a wristwatch and may be used together with a sleep diary.
- Multiple sleep latency tests determine how long it takes you to fall asleep during the day. You’ll need to take four to five naps, two hours apart.
- Polysomnogram testing requires that you spend the night in a medical facility. You’ll be monitored while you sleep, with electrodes attached to your scalp to measure brain activity, heart rate and rhythm, eye movement, muscle movement, and breathing. This test can also detect sleep apnea.
- A spinal tap, or lumbar puncture, is used to collect cerebrospinal fluid (CSF). Hypocretin in CSF is expected to be low in people with narcolepsy. For this test, your doctor will insert a thin needle between two lumbar vertebrae.
Narcolepsy has no cure. It’s a chronic condition that lasts a lifetime. The goal of treatment is to control symptoms and improve daytime functioning. Stimulants, lifestyle adjustments, and avoidance of hazardous activities are all used to treat this disorder. There are several classes of medications used to treat narcolepsy, including the following:
- Stimulants such as armodafinil and dextroamphetamine (Dexedrine, DextroStat) and methylphenidate (Ritalin) may be used to improve wakefulness. Armodafinil is usually the first medication to be prescribed because it’s the least likely to be abused.
- Tricyclic antidepressants can reduce cataplexy, sleep paralysis, and hallucinations. These medications can have unpleasant side effects such as dry mouth and urinary retention.
- Selective norepinephrine reuptake inhibitors, or SNRIs, can help keep you awake. Norepinephrine is a natural stimulant and a part of the sympathetic nervous system. Preventing the reabsorption of norepinephrine prolongs its activity and keeps sleep at bay.
- Xyrem (sodium oxybate) can be used to help you sleep at night.
- Selective serotonin reuptake inhibitors, or SSRIs, can help improve your mood.
Here are some steps you can take to make living with narcolepsy easier and safer:
- Tell teachers and supervisors about your condition. If you do fall asleep, they should understand the reason for it.
- Be aware that some narcolepsy treatments will cause you to test positive for stimulants on drug screens. Talk to your employer in advance to prevent misunderstandings.
- Eat light or vegetarian meals during the day. Don’t eat a heavy meal before important activities.
- Try taking 10-15 minute naps after meals.
- Schedule naps throughout the day. This may help you avoid daytime drowsiness.
- Avoid nicotine and alcohol. They can make symptoms worse.
- Exercise regularly. Try exercising four to five hours before bedtime. This can help you rest better at night. It can also help keep you alert during the day.
- Some states may limit driving privileges for people with narcolepsy. Be sure to check with your local department of motor vehicles. They can help keep you from endangering anyone or breaking the law.
Living with narcolepsy can be challenging. It can be stressful to have an episode at an awkward time, and it’s possible for you to injure yourself or others during an episode. By following the above tips, you can manage your narcolepsy and continue to live a healthy life.