Narcolepsy is a sleep disorder characterized by excessive sleepiness, sleep paralysis, hallucinations, and in some cases episodes of cataplexy (partial or total loss of muscle control, often triggered by a strong emotion such as laughter). Narcolepsy occurs equally in men and women and is thought to affect roughly 1 in 2,000 people. The symptoms appear in childhood or adolescence, but many people have symptoms of narcolepsy for years before getting a proper diagnosis.
People with narcolepsy feel very sleepy during the day and may involuntarily fall asleep during normal activities. In narcolepsy, the normal boundary between awake and asleep is blurred, so characteristics of sleeping can occur while a person is awake. For example, cataplexy is the muscle paralysis of REM sleep occurring during waking hours. It causes sudden loss of muscle tone that leads to a slack jaw, or weakness of the arms, legs, or trunk. People with narcolepsy can also experience dream-like hallucinations and paralysis as they are falling asleep or waking up, as well as disrupted nighttime sleep and vivid nightmares.
Narcolepsy symptoms can vary from person to person, with some cases more severe than others. There are two main types of narcolepsy:
In addition to the other narcolepsy symptoms, people who have narcolepsy with cataplexy experience sudden muscle weakness and lose control of the muscles in their face, arms, legs, or torso. This causes the person to slur words, have a sagging jaw, collapse, or slump over and be unable to move. During cataplexy, the person is awake. An episode can last for seconds or up to one or two minutes and is often triggered by a strong emotion, such as excitement or laughter.
A person with narcolepsy without cataplexy has all the symptoms of narcolepsy extreme sleepiness, sleep attacks, dream-like hallucinations and paralysis while falling asleep or waking up, and disrupted nighttime sleep), but without episodes of sudden muscle weakness triggered by strong emotions. This type of narcolepsy can be less severe than narcolepsy with cataplexy.
Narcolepsy affects the systems in the brain that help us stay awake. Normally, alerting signals come from the brain stem, a region deep in the brain responsible for many basic functions. These signals spread out and “wake up” the rest of the brain. Meanwhile, a cluster of cells in another nearby region called the hypothalamus produce the chemical hypocretin. Hypocretin activates and maintains the action of those alerting signals coming from the brain stem.
In a person with narcolepsy, the cells in this specialized region of the hypothalamus have died off. Even though it’s a relatively small cluster of cells, the impact on waking and sleep is dramatic. Without hypocretin, it’s hard for a person to stay awake for long periods of time, and they experience overlaps between waking and sleep—such as vivid hallucinations and paralysis when falling asleep or waking up.
The loss of hypocretin also affects the action of other key chemicals in the brain, such as dopamine, serotonin, and norepinephrine. This is why antidepressants (which act on these neurotransmitters) are sometimes prescribed for narcolepsy.
Scientists are working on ways to target and stimulate hypocretin receptors, as a way to mimic the presence of the chemical. They are also working on understanding how hypocretin cells are lost in the first place (the autoimmune response) so they can target the first stage of the process and halt the development of narcolepsy symptoms.
Narcolepsy with cataplexy is caused by a lack of the chemical hypocretin in the brain. Hypocretin is an important chemical for regulating wakefulness and rapid eye movement (REM) sleep. Narcolepsy without cataplexy includes most of the same symptoms, but its cause is unknown. Injuries to the hypothalamus and brain stem, tumors, and stroke are under investigation.
The current understanding of narcolepsy is that it begins with an underlying genetic predisposition; a person is born with certain genes that put them at greater risk for developing narcolepsy. In childhood or the teen years, an event like an infection may trigger the onset of narcolepsy. Instead of the immune system simply attacking the infection, it becomes confused and attacks the specialized cells in the brain that produce hypocretin. The loss of hypocretin-producing cells leads to the symptoms of narcolepsy. Because the immune system is believed to be responsible for the loss of these cells, narcolepsy is considered an autoimmune disease. One of the triggering events linked to narcolepsy is an infection of the H1N1 influenza virus.
The loss of hypocretin in the brain makes it hard for a person to stay awake. It also allows REM sleep to occur in moments when it normally does not. A person with narcolepsy can enter REM sleep directly from a waking state, rather than going through the normal progression from awake, through deep sleep, and eventually into REM sleep.
During normal sleep cycles, we progress through stages of non-rapid eye movement (NREM) sleep and eventually into rapid eye movement (REM) sleep. When we enter REM sleep, we are more likely to dream, most muscles in the body become paralyzed, and our eyes move back and forth behind the eyelids.
For a person with narcolepsy, aspects of REM sleep overlap with being awake. This is why during the day, when the person is awake, a strong emotion can trigger cataplexy and the paralysis of REM, causing the loss of muscle control seen in cataplexy. This is also what causes a person with narcolepsy to experience vivid dream-like hallucinations and paralysis while falling asleep or waking up.
Currently there is no cure for narcolepsy, but medications and behavioral treatments can improve symptoms for people so they can lead normal, productive lives.
To vastly improve the quality of your life, consider implementing coping strategies such as,
Narcolepsy often begins during childhood and teens year, so it’s important to find ways to manage symptoms in the learning environment. Students with narcolepsy can learn and perform well in school with the right support.
The symptoms of narcolepsy can, at first, be difficult to distinguish from other issues like sleep deprivation—especially in teens. Behaviors like falling asleep in class, poor grades, or not being able to complete homework or other assignments can be early clues. If narcolepsy is diagnosed, it’s an opportunity for the student, parents, and teachers to meet and discuss how to support the student in school. Educate teachers about narcolepsy, describing it as a sleep disorder that has a chemical cause in the brain and is not a result of bad sleep habits, lack of motivation, or the need for more sleep.
It may be helpful to make arrangements with the school nurse to understand the child’s medications and accommodate the need for short, scheduled naps during school hours. A letter from the child’s doctor to the school nurse may be needed.
Kids can develop self-awareness about what helps them feel best, for example taking a nap in the nurse’s office, getting up and walking around the classroom, exercising, sitting on a yoga ball instead of a chair, chewing gum, sitting near the window or at the front of the class—all these habits can help, with the support of the teacher.
It may be a good idea to tell your co-workers, supervisor, or human resources department about your diagnosis, if it’s appropriate. Give a short, clear definition of what narcolepsy is and what the symptoms look like. Describe possible scenarios where symptoms may occur (for example, an episode of cataplexy when laughing), and be ready with concrete plans that you believe help you manage symptoms and increase productivity at work. Depending on your work setting, employers may be obligated to make accommodations.
Helpful strategies for staying alert and productive at work are to stand up periodically, for example while talking on the phone or in conversation with a co-worker; and walk around the office or outside when possible. Taking brief naps during the workday may be essential, so assess the best strategy for this—whether it’s napping in your office or signing up for another room for 30 minutes to allow for a nap. Explain to your co-workers and supervisor that a short nap increases your productivity.
Narcolepsy symptoms can be very dangerous. Falling asleep or losing muscle control during normal daytime activities poses a serious safety risk. Some of the most dangerous scenarios are driving a car, operating machinery, and cooking. It takes only a few seconds of intense sleepiness or loss of muscle control at the wheel for an accident to occur. Research suggests that people with narcolepsy are more likely to fall asleep while driving and more likely to be involved in a car accident.
The safety risks of narcolepsy make it important to seek help, consider treatment options, and manage alertness and productivity through behavioral and lifestyle changes. Self-awareness and education is key in managing narcolepsy and maintaining a productive and safe daily life.
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