Narcolepsy is a long-term neurological condition that causes fragmented sleep and excessive daytime sleepiness.
It also features abnormal rapid eye movement (REM) sleep and can involve cataplexy, or brief attacks of muscle weakness and tone that can lead to body collapse.
Narcolepsy can range in severity from mild to severe. In severe cases, it can negatively impact social activities, school, work, and overall health and well-being. A person with narcolepsy may fall asleep at any time, such as while talking or driving.
Symptoms tend to appear in a person’s teenage years or early 20s or 30s. In the United States, it is 50% more likely to affect females than males. Experts believe that around 1 in 2,000 people have narcolepsy.
It may affect 135,000–200,000 people in the U.S. at any one time.
This article outlines the symptoms, causes, and treatment options associated with narcolepsy.
Narcolepsy is a sleep disorder that features excessive daytime sleepiness.
In a typical sleep cycle, a person will first enter the early stage of sleep, then the deeper sleep stages. This is when REM sleep occurs. It takes around 60–90 minutes to reach the stage of REM sleep.
For people with narcolepsy, however, REM sleep occurs within 15 minutes in the sleep cycle and intermittently during the waking hours. It is during REM sleep that vivid dreams and muscle paralysis occur.
It can also disrupt nighttime sleep patterns. Overall, however, a person with narcolepsy usually spends the same amount of time asleep as a person without the condition.
Excessive daytime sleepiness
People with narcolepsy will usually have a persistent feeling of sleepiness with a tendency to doze off at intervals throughout the day, often at inappropriate times.
They may also experience:
- brain fog
- poor concentration
- decreased energy
- memory lapses
- a depressed mood
Hypnogogic hallucinations are vivid, often frightening sensory hallucinations that occur while falling asleep. They may result from the blend of wakefulness and dreaming that occurs with REM sleep.
Cataplexy refers to sudden muscle weakness that affects the face, neck, and knees. Some people will have only mild weakness, such as a head or jaw drop, but some may collapse to the ground.
This weakness is temporary, lasting 2 minutes or less, but it can lead to falls and other accidents.
Triggers include strong emotions, such as surprise, laughter, or anger.
This is an inability to move or speak while falling asleep or waking up. Episodes can last from a few seconds to several minutes. After the episode, people will recover their full capacity to move and speak.
There is currently no cure for narcolepsy, but medical treatment and lifestyle tips may help. The following sections will look at these in more detail.
One way to manage narcolepsy is through behavior modification. A person may need naps of 15–20 minutes throughout the day.
A doctor may also prescribe a central nervous system stimulant to prevent sleepiness, though no drugs are likely to be completely effective.
Modafinil and armodafinil are usually the first choices.
The other drugs are older and more likely to be habit-forming. They can also lead to irritability, anxiety, changes in heart rhythm, and other side effects.
Sodium oxybate has approval from the Food and Drug Administration (FDA) for treating excessive daytime sleepiness, poor nighttime sleep, and cataplexy. It has few side effects and very little interaction with other drugs.
Antidepressant drugs can help a person manage cataplexy, but they can have adverse effects, such as high blood pressure and changes in heart rhythm.
The doctor may adjust the treatment over time as symptoms change.
For quality of life
Narcolepsy can have a significant impact on a person’s quality of life. A doctor may recommend the following options to help people manage these challenges:
- gaining emotional support from loved ones
- seeking mental health counseling
- seeking help with obtaining medications and completing disability forms, if appropriate
- educating oneself about how drugs and alcohol can impact narcolepsy
People should avoid any activity that could pose a health threat, such as using machinery or driving, until treatment is able to improve their condition.
The following lifestyle tips may help:
- Take regular naps during the day.
- Follow a regular sleep schedule.
- Follow any treatment plan a doctor recommends.
- Exercise every day for at least 20 minutes, but stop exercising 4–5 hours before bedtime.
- Avoid caffeine or alcohol several hours before going to bed.
- Avoid smoking, especially before bedtime.
- Avoid eating heavy meals near bedtime.
- Plan to relax before going to bed, such as by taking a bath.
- Ensure that the bedroom is a comfortable temperature.
- Take precautions when driving.
The exact cause of narcolepsy is unknown, but it likely involves a deficiency in hypocretin, or orexin. This is a chemical the brain needs to stay awake.
Some genetic features may increase the risk of narcolepsy, and it sometimes runs in families. According to the Genetic and Rare Diseases Information Center, it probably results from a combination of genetic and environmental factors.
Hypocretin is a neurotransmitter. It controls whether a person is asleep or awake by acting on different groups of nerve cells, or neurons, in the brain. The hypothalamus region of the brain produces hypocretin.
People with type 1 narcolepsy have low levels of hypocretin, but those with type 2 do not.
A person needs hypocretin to stay awake. When it is not available, the brain allows REM sleep phenomena to intrude into normal waking periods. In people with narcolepsy, this leads to both excessive daytime sleepiness and nighttime sleeping problems.
A brain injury, tumor, or other condition that affects the brain can also sometimes lead to narcolepsy.
Initially, doctors may misdiagnose narcolepsy. This is because it tends to resemble other conditions, such as:
In fact, it can take 5–10 years to confirm a diagnosis.
To determine whether or not a person has narcolepsy, the doctor will:
- take a thorough medical and sleep history
- perform a physical examination
- conduct sleep studies, such as polysomnography and a multiple sleep latency test
Sleep studies can help confirm a diagnosis of narcolepsy.
A person will undergo polysomnography in a sleep clinic. They will sleep in the clinic overnight while a machine measures their sleep patterns.
The multiple sleep latency test will take place a few hours after the polysomnography.
Questions a healthcare professional may ask on obtaining a person’s sleep history may include:
- Are you sleepy most of the day?
- How many hours are you sleeping at night?
- Do you feel rested on waking?
- Are your naps refreshing?
- Do you experience unusual sensations as you are falling asleep?
- Are you ever unable to move as you fall asleep or when you first awake?
- Do you have muscle weakness or collapse when laughing or angry?
Keeping a sleep journal may also help with diagnosis.
There is currently no cure for narcolepsy, but taking prescription medication and modifying some lifestyle habits can help a person manage the condition and stay safe.
Scientists are investigating how genetic and other factors may affect the condition, and there is hope that they will find more effective treatments with time.
Organizations such as WUN can help people keep up-to-date with the latest developments. They invite people to join in the search for a cure by participating in research projects.