What is narcolepsy?
Narcolepsy is a neurological (nervous system) disorder that affects the brain’s ability to control sleep and wakefulness. If you have narcolepsy, you experience excessive daytime sleepiness and may have uncontrollable episodes of falling asleep during the daytime. These sudden sleep “attacks” may occur during any type of activity and at any time of the day.
Who gets narcolepsy?
Approximately one in 2,000 Americans has narcolepsy. The disorder affects males and females equally. Up to 10% of people who have narcolepsy have a relative who also has the disorder. Narcolepsy occurs in people of all ages, but the first sign of daytime sleepiness usually appears in the teenage years or twenties. Because narcolepsy symptoms mimic depression, other sleep disorders, or other illnesses, it may go undiagnosed and untreated for years.
Are there different types of narcolepsy?
Yes, there are two types of narcolepsy:
- Type 1 narcolepsy (previously called narcolepsy with cataplexy [see symptoms section for definition]). Persons with type 1 narcolepsy have excessive daytime sleepiness plus cataplexy and/or low levels of a chemical in the brain called hypocretin.
- Type 2 narcolepsy (previously called narcolepsy without cataplexy). Persons with type 2 narcolepsy have excessive daytime sleepiness but do not have cataplexy and have normal levels of hypocretin.
Symptoms and Causes
What causes narcolepsy?
Scientists have discovered that people with narcolepsy have a loss of a neurotransmitter (chemical signal) in the brain called hypocretin. Hypocretin is important for regulating the sleep/wake cycle including the rapid eye movement (REM) sleep state. A shortage of hypocretin causes excessive sleepiness, and features of REM sleep (also called “dreaming sleep”) become present during wakefulness.
Other possible factors scientists think play a role in narcolepsy include:
- An autoimmune disorder. A person’s immune system attacks the brain cells that produce hypocretin, resulting in a shortage of this chemical.
- Family history. Some persons with narcolepsy have close relatives with similar symptoms.
- Brain injury or tumor. In a small number of patients, the area of brain that controls REM sleep and wakefulness can be injured by trauma, tumor or disease.
- Environmental toxins, such as pesticides, heavy metals and secondhand smoke.
What are the symptoms of narcolepsy?
Symptoms of narcolepsy include:
- Excessive daytime sleepiness (EDS): All patients with narcolepsy have this symptom. In general, EDS interferes with normal activities (work, school, home life, social activities) every day. Although brief naps during the day may help you feel rested and alert, tiredness returns within one to two hours. People with EDS report mental cloudiness, a lack of energy and concentration, memory lapses, a depressed mood and/or extreme exhaustion.
- Cataplexy: This symptom is a sudden loss of muscle tone or strength brought on by strong emotions, such as laughter, fear, surprise, stress or anger. Attacks can occur any time you are awake. The attacks range from a brief buckling of the knees or slackness in the jaw or drooping of eyelids to total body paralysis with collapse. Cataplexy usually lasts a few seconds to several minutes. You remain fully conscious during these attacks. The rate of attacks ranges from a few in a lifetime to several per day. Although scary, there’s no damage from these episodes.
- Disrupted nighttime sleep: This symptom is described as frequent awakenings during the night.
- Sleep paralysis: This symptom is the inability to move or speak just before falling asleep or just after waking up. Episodes of sleep paralysis usually go away after a few seconds to a few minutes.
- Hallucinations: Usually, these delusional experiences are vivid and may be frightening. The hallucinations occur just before falling asleep (called hypnagogic hallucinations) or just after waking up (called hypnopompic hallucinations). Hallucinations are mainly visual (seen), but you can also feel like you can hear, taste or smell things. Examples include seeing a person or animal in the room, feelings of floating or sensations of being touched, and hearing an alarm or voices.
- Automatic behavior: This symptom is described as falling asleep for several seconds but continues to perform routine tasks, such as eating, talking, driving or writing, without any awareness or later memory of ever doing the task.
Diagnosis and Tests
How is narcolepsy diagnosed?
Narcolepsy is diagnosed after your healthcare provider performs a detailed medical and sleep history, physical examination, medication history and sleep studies (which are performed in a sleep disorders center). You may also be asked to wear a wrist motion sensor (called an actigraph) for a few weeks or keep a sleep diary, which consists of keeping notes about how easy it is for you to fall asleep and stay asleep, how many hours of sleep you get each night and how awake you feel during the day.
Two essential sleep studies to confirm a diagnosis of narcolepsy are the polysomnogram (PSG) and the multiple sleep latency test (MSLT). These tests are usually performed in a sleep disorders center and require an overnight stay.
- The PSG is an overnight test that takes continuous multiple measurements, including heart rate, oxygen level, breathing rate, eye and leg movements and brain waves while you sleep. A PSG reveals how quickly you fall asleep, how often you wake up during the night and how often REM sleep is disturbed (a common finding in people with narcolepsy). This study also helps determine if your symptoms are caused by another condition, such as obstructive sleep apnea. Most people with narcolepsy show disruptions in normal sleep patterns, with frequent awakenings.
- The MSLT is performed during the daytime, the day after the PSG test. During MSLT, you will take five short naps, scheduled two hours apart. The MSLT measures how quickly you fall asleep and how quickly you enter into REM sleep.
Management and Treatment
How is narcolepsy treated?
Management of narcolepsy consists of medications and lifestyle changes. The goal of medications is to reduce daytime sleepiness and improve alertness.
A number of medications with varying mechanisms of action in the brain are now available for the treatment of excessive daytime sleepiness (EDS).
These agents help patients stay awake during the day but do not treat cataplexy or other REM sleep-related signs of narcolepsy. Modafinil (Provigil®) or armodafinil (Nuvigil®) are often tried first because they have fewer side effects and are less addictive than traditional stimulants.
More recently approved medications are solriamfetol (Sunosi®) and pitolisant (Wakix®). Solriamfetol is used to improve wakefulness in adults with narcolepsy. Pitolisant (Wakix®) is the first medication approved to treat EDS in narcolepsy that is not classified as a controlled substance (substances with greater risk of abuse or addiction). Solriamfetol and pitolisant work on the brain in different ways than other available agents.
Sodium oxybate (Xyrem®) is the only FDA-approved medication used to treat daytime sleepiness and cataplexy in patients with narcolepsy. It is taken in liquid form before bedtime and 2.5 to 4 hours later and not during the daytime. Due to its high sodium content, patients using sodium oxybate are advised to limit salt in the diet.
Once the mainstay of narcolepsy therapy, traditional stimulants such as amphetamine/dextroamphetamine or dextroamphetamine mixed salts (Adderall®, Dexedrine®) and methylphenidate (Ritalin®, Focalin®, Concerta®) are very effective for treating EDS but have a higher risk of side effects than wake-promoting agents. Stimulants can produce side effects similar to that seen with caffeine, such as agitation, nervousness and palpitations. They are generally started at a low dose and increased gradually as needed. Careful monitoring is required, as high blood pressure, heart arrhythmias (irregular heartbeats) and drug abuse have been reported.
Cataplexy, hallucinations, disrupted nighttime sleep and sleep paralysis are often treated with two types of antidepressant medications: tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs). Examples of TCAs include protriptyline (Vivactil®), clomipramine (Anafranil®) and desipramine (Norpramin®). Examples of SSRIs include fluoxetine (Prozac®), atomoxetine (Strattera®) and sertraline (Zoloft®). SSRIs generally have fewer side effects than TCAs. These agents are prescribed off-label, meaning that clinical trials have not been performed and the FDA has not approved them for the treatment of narcolepsy.
It may take several weeks and/or several trials of different medications to find which one(s) work best for you and which dosage works best. Your doctor may also recommend avoiding antihistamine products (an ingredient in many cold products), as these products block the action of a substance in the blood (histamine) that helps you stay awake.
What lifestyle changes can help better manage narcolepsy?
Consider the following:
- Follow a regular sleep/wake schedule. Go to bed and wake up at about the same time every day. Avoid intentional sleep loss, such as staying awake late on weekends.
- Keep your bedroom quiet, dark, cool and comfortable. Do not watch TV or bring computers or phones into bed with you.
- Avoid alcohol and caffeine (colas, coffee, teas, energy drinks and chocolate) for several hours before bedtime.
- Avoid smoking, especially in the evening.
- Exercise at least 20 minutes per day. Do not exercise within three hours of bedtime.
- Don’t eat large, heavy meals or a lot of liquids close to bedtime.
- Relax before bedtime. Take a warm bath, meditate, perform some gentle yoga moves, listen to soft music, expose yourself relaxing scents such as peppermint, eucalyptus or lavender.
- Take short naps (20 to 30 minutes) at times when you are feeling most sleepy, if possible.
Can narcolepsy be prevented?
There is not much that can be done to prevent narcolepsy. Narcolepsy is caused by a loss of a neurotransmitter (chemical signal) in the brain called hypocretin. Hypocretin is important for regulating the sleep/wake cycle. Other causes include an autoimmune disease that could be attacking the cells that produce hypocretin, family history, brain injury or tumor, infections or exposure to toxins.
Outlook / Prognosis
What should I expect if I have narcolepsy?
There is no cure for narcolepsy. It is a life-long sleeping disorder. However, it usually does not worsen with age. The use of medications and lifestyle changes can help improve narcolepsy symptoms.
How can I better live my day-to-day life with a diagnosis of narcolepsy?
Here are some tips:
Driving: Driving can be dangerous if you have narcolepsy. People with narcolepsy have a greater risk for motor vehicle accidents. Ask your doctor if it safe for you to drive.
Some safety tips if you drive include:
- Take a short nap before you drive.
- Drive for only short stretches of time. Stop, get out of your vehicle, walk around and/or stretch and consider taking a short nap before continuing to drive.
- Keep yourself engaged while driving. Sing to the music, talk with others in the car — or better yet, let them drive if possible.
- Find out about car pool options or consider Uber or Lyft or other driver services.
Work: If you are working, you may want to look into the American with Disabilities Act. This law requires employers to provide reasonable work provisions for employees with disabilities. Your employer may allow you to adjust your work schedule or take brief rest breaks during the work day.
Support: Ask your doctor about local support groups (also see resource section of this article). Support group allow you to meet and share experiences and solutions to common issues and concerns all group members have about narcolepsy. Share your thoughts and feelings with family and friends too. Tell them how they might be able to help you (for example, can they help you with driving/errand runs).
Narcolepsy is a draining disorder that interferes with all aspects of a person’s life including school, work and relationships. Consider seeking the help of a counselor if you are having a difficult time coping with aspects of your life or are experiencing stress, fear, depression or anxiety from having narcolepsy.
When should I call my healthcare provider?
If you or a loved one believe you have narcolepsy, see your healthcare provider. He or she may refer you to a sleep specialist or sleep center for additional evaluation. Early diagnosis and treatment can help reduce symptoms. Also continue to share your issues and concerns with your healthcare professional. Your doctor may adjust the dose of your medication, try other medications, or make other recommendations to improve your symptoms to achieve the highest degrees of alertness and daytime functioning possible.