What Is Narcolepsy?
Narcolepsy (NAR-ko-lep-see) is a disorder that
causes a person to have difficulty staying awake. Narcolepsy can cause a person
to suddenly fall asleep during the day. These sleep attacks occur
even after getting enough sleep at night. The unusual sleep pattern that people
with narcolepsy have can affect their schooling, work, and social life.
The two main types of sleep are rapid eye movement
(REM) sleep and nonrapid eye movement (NREM) sleep. During REM sleep, your eyes
move rapidly even though your eyelids stay shut. Dreaming mainly happens during
REM sleep, when your body becomes limp and you are unable to move your muscles.
This temporary inability to move prevents you from acting out any dreams that
you may be having.
Normally, when people fall asleep they first have
NREM sleep. Then they go through a period of REM sleep. People with narcolepsy
have a different sleep pattern. They often fall into REM sleep before NREM
sleep. Also, in people with narcolepsy, the fine line between being asleep and
being awake can be blurred. They often find that certain aspects of REM sleep
can happen while they are awake. This causes them to:
- Suddenly lose muscle tone and control when awake
(cataplexy). This can appear to be muscle weakness and sometimes can trigger
the body to collapse.
- Not be able to move or speak while falling asleep
or waking up (sleep paralysis).
- Have vivid dreams while falling asleep or waking
up (hallucinations).
Effects of Narcolepsy
People with narcolepsy often fall asleep without
warning at inappropriate times. Sleep attacks dont just happen during
quiet times, such as when reading or watching TV. These attacks can occur
during driving, eating, or other activities and can cause:
- Accidents and injuries
- Problems at work or at school
- Social problems
- Impaired memory, thinking, or ability to
concentrate
- Depression
Outlook
There is no cure yet for narcolepsy. This lifelong
condition can be disabling if left untreated. But medicines and lifestyle
changes can improve the symptoms of narcolepsy so that it is easier to live
with.
What Causes Narcolepsy?
Research suggests that the cause of narcolepsy is a
lack of the chemical in the brain called hypocretin. This chemical stimulates
brain cells and helps promote wakefulness. It is not known why hypocretin is
missing in people who have narcolepsy. Some factors that may work together to
cause a lack of hypocretin include:
- Infection
- Loss of certain brain cells due to brain injury,
toxins, and/or the bodys destruction of its own tissues (autoimmune
reaction)
- Changes in hormones
- Stress
One out of 10 people with narcolepsy and cataplexy
has a close relative with the same symptoms. This suggests that some people may
inherit the tendency to develop narcolepsy.
Who Is At Risk for Narcolepsy?
Narcolepsy may affect 150,000 (1 in 2,000) people or
more in the United States. It usually first occurs between the ages of 15 and
30 and affects both men and women. The symptoms can start suddenly or appear
gradually. The condition is difficult to diagnose without medical tests. Often
people live with mild symptoms, such as daytime sleepiness and muscle weakness,
for several years before narcolepsy is diagnosed. Narcolepsy can also develop
later in life or in children, but it is rare before age 5. Factors that may
increase the risk of developing narcolepsy include having:
- A brother, sister, or parent with narcolepsy
- Certain thyroid disorders
- Diabetes
- A disease in which the bodys infection
fighting system mistakenly attacks the bodys own organs and tissues (an
autoimmune disorder)
What Are the Signs and Symptoms of Narcolepsy?
The major symptom of narcolepsy is excessive daytime
sleepiness with sleep attacks. People with narcolepsy may also have one or more
of the following signs and symptoms:
- Sudden loss of muscle tone and control (muscle
weakness) over parts or all of the body while awake (cataplexy)
- Sudden inability to move or speak while falling
asleep or waking up (sleep paralysis)
- Vivid dreams while falling asleep or waking up
(hallucinations)
Daytime Sleepiness
All people with narcolepsy have excessive daytime
sleepiness. This is usually the first symptom of the condition. They also may
have sudden, irresistible urges to sleep during the day (sleep attacks). They
usually fall asleep for just a few seconds or minutes. Rarely, they may fall
asleep for as long as an hour or more. Daytime sleepiness can cause:
- Mental cloudiness or fog
- Memory problems
- Problems focusing
- Lack of energy
- Depression
- Extreme exhaustion
Cataplexy
Nearly 3 out of 4 people with narcolepsy (75
percent) experience sudden muscle weakness while they are awake. This is called
cataplexy, and it is similar to the paralysis that occurs during dream sleep.
Mild attacks of muscle weakness can cause:
- Head nodding
- Drooping eyelids
- Difficulty speaking
- Difficulty moving arms or hands or a weakened
grip
- Buckling of the knees
Severe attacks of narcolepsy may cause complete
paralysis and falls. Attacks often last less than 2 minutes, and they may only
last a few seconds. During both mild and severe attacks, the person stays fully
conscious.
The sudden attacks of muscle weakness in narcolepsy
can happen at any time. But these attacks are often triggered by strong
emotions, including:
- Laughter
- Anger
- Fear
- Excitement
Attacks of muscle weakness and tone are sometimes
the first symptom of narcolepsy that is noticed. But usually this symptom
occurs weeks or months after people who have narcolepsy first start to
experience excessive sleepiness during the day.
Sleep Paralysis
People with narcolepsy may suddenly not be able to
move or speak while falling asleep or waking up. They are fully conscious
during these periods of sleep paralysis. The paralysis usually lasts just a few
seconds or minutes, but it can be scary. Sleep paralysis is similar to the
paralysis that happens in rapid eye movement (REM) sleep. Not all people with
narcolepsy have sleep paralysis.
Hallucinations
Some people with narcolepsy have vivid dreams while
they are falling asleep, waking up, or dozing. These hallucinations differ from
normal dreams because they seem very real and include sights, sounds, smells,
tastes, and touch. People with narcolepsy may say these hallucinations are
scary like a nightmare. The hallucinations can occur with sleep paralysis.
Other Symptoms
Some people with narcolepsy have difficulty staying
asleep through the night. These frequent awakenings may start years after
experiencing the first symptoms of narcolepsy. Another symptom of narcolepsy is
to carry out certain actions without awareness. This is called automatic
behavior. For example, if people with this symptom are writing, they may
scribble rather than form words. When driving, people with automatic behavior
may get lost or have an accident because of periods when they arent aware
of what they are doing. People usually do not remember such automatic
behavior.
How Is Narcolepsy Diagnosed?
Doctors will base a diagnosis of narcolepsy on the
patients symptoms, family history of narcolepsy, physical exam, and test
results. The symptoms people have are often distinct enough for doctors to
diagnose narcolepsy. But laboratory tests are needed to confirm the diagnosis
and determine the best treatment. These tests may require the patient to visit
a sleep disorders center for an overnight evaluation.
Symptoms and Family History
If your doctor suspects you have narcolepsy, he or
she will ask whether you have:
- Daytime sleepiness and sleep attacks
- Sudden and temporary losses of muscle tone and
control (cataplexy)
- Vivid dreams while falling asleep or waking up
(hallucinations)
- An inability to move or speak while falling
asleep or waking up (sleep paralysis)
If you have any of these symptoms, your doctor will
want to know when you first developed them and if they interfere with sleep or
daily activities. The doctor may also ask questions about your sleep habits and
how you feel and act during the daytime. To help you answer those questions,
you may be asked to keep a sleep diary for a few weeks. In this daily dairy you
may be asked to write:
- When you go to bed and get up
- How long it takes you to fall asleep, and how
often you wake up during the night
- If you snore loudly and frequently, or wake up
gasping or feeling out of breath
- How refreshed you feel when you wake up, and how
tired you feel during the day
- How often you doze off or have trouble staying
awake during the day
Doctors also usually ask whether you have symptoms
of other sleep disorders that cause daytime sleepiness. You may also be asked
if you have any relatives with narcolepsy.
Physical Exam
Your doctor will examine you to see if you have
signs of other possible causes for your symptoms. These causes include:
- Infections
- Certain thyroid diseases
- Drug or alcohol use
- Other medical or sleep disorders
This part of the diagnosis usually requires your
doctor to do a complete physical exam.
Sleep Specialist
If your doctor suspects you have narcolepsy, he or
she will likely suggest you see a sleep specialist who may recommend special
sleep
tests. The sleep specialist will confirm a diagnosis of narcolepsy,
diagnose another sleep disorder, or rule out a specific sleep disorder as the
cause of your symptoms, based on:
- The results of your sleep tests
- Your symptoms
- Your sleep habits as recorded in a sleep
diary
Narcolepsy is easier to diagnose if you have more
symptoms than just daytime sleepiness and sleep attacks.
Sleep Tests
Sleep tests are usually done at a sleep disorders
center. For some sleep tests, you may need to sleep overnight at the center.
Other sleep tests can be done during the day. The three tests most often used
to diagnose narcolepsy are:
- Polysomnogram (PSG)
- Multiple sleep latency test (MSLT)
- Hypocretin test
Polysomnogram
For this study, you sleep overnight at a sleep
center. While you are sleeping, the staff at the center use various devices to
measure your brain activity, breathing, and movements. The signs of narcolepsy
this test can reveal include:
- Falling asleep quickly
- Entering rapid eye movement (REM) sleep soon
after falling asleep
- Waking up often during the night
Multiple Sleep Latency Test
This test is usually done during the day after an
overnight PSG. Also called a nap study, the MSLT measures how easy it is for
you to fall asleep during the day. You are asked to take short naps about every
2 hours. The test records eye movements, muscle tone, and brain activity with
small devices attached to the head. The signs of narcolepsy this test can
reveal are quickly falling asleep during the day (after a full nights
sleep) and entering REM sleep soon after falling asleep.
Hypocretin Test
This test measures the levels of hypocretin in the
fluid that bathes your spinal cord. Low levels of hypocretin make it likely
that you have narcolepsy.
How Is Narcolepsy Treated?
There is no cure for narcolepsy, but many of the
symptoms of this disorder can be relieved with medicines and lifestyle changes.
Treatment for narcolepsy is based on the type and severity of symptoms. Some
medicines help relieve daytime sleepiness, while other medicines may help
prevent the sudden loss of muscle tone and movement (cataplexy) or vivid dreams
while falling asleep or waking up (hallucinations) that some people with
narcolepsy have. Not all medicines work for everyone. It may take weeks to
months for your doctor to find the best treatment for you.
Medicines To Relieve Daytime Sleepiness
Doctors may prescribe stimulants to increase daytime
alertness in narcolepsy patients, including:
- Modafinil
- Pemoline
- Methylphenidate
- Amphetamines
Modafinil is the newest stimulant for treating
daytime sleepiness in people with narcolepsy. Modafinil may not be strong
enough to relieve sleepiness in everyone with narcolepsy, and Modafinil is
sometimes prescribed with another stimulant to give more complete relief from
daytime drowsiness.
Medicines To Relieve Other Symptoms
Several different antidepressant medicines can be
used to treat the sudden loss of muscle tone (cataplexy), vivid dreams while
falling asleep and waking up (hallucinations), and inability to move or speak
when falling asleep or waking up (sleep paralysis) that affect some people with
narcolepsy. These medicines affect the chemicals in the brain that seem to play
a role in narcolepsy. People with cataplexy need to check with their doctor to
find which treatment will work best for them.
Lifestyle Changes
If you have narcolepsy, it is important to combine
any drug treatments with lifestyle changes that help lessen symptoms. By taking
regular naps at times during the day when you are feeling the sleepiest, you
may need less medicine to treat daytime sleepiness. You should also try to go
to sleep and wake up at the same time each day, and give yourself at least 8
hours to sleep each night. To make it easier to fall asleep at night, you can:
- Do something relaxing before bedtime, such as
taking a warm bath.
- Keep your bedroom or sleep area quiet,
comfortable, and free of light and distractions, such as a TV or computer.
- Exercise regularly, but not within 3 hours of
bedtime.
A few hours before bedtime, you should also try to
avoid substances that can make it hard to fall or stay asleep. These substances
include:
- Caffeine in coffee, chocolate, and certain soft
drinks and teas
- Tobacco
- Alcohol
- Certain over-the-counter and prescription
medicines
Living With Narcolepsy
Narcolepsy is a lifelong condition. Although there
is no cure for this condition, symptoms often improve with ongoing treatment.
Most people with narcolepsy can live near-normal lives. The condition can be
dangerous if sleep attacks or sudden loss of muscle tone occur while driving or
using machinery. Even when these episodes occur at other times, they can cause
injury or impair performance in school and on the job. To help avoid harm, try
to:
- Avoid being alone when you are likely to have a
sleep attack.
- Take a nap before those times during the day when
an attack is likely.
- Safeguard your home and workspace.
- Seek help from family, friends, coworkers, and
your doctor.
- Take your narcolepsy medicine on a schedule that
will help lessen the risk that you will have severe side effects while you are
alone.
Driving
Driving can be dangerous for people with narcolepsy.
You need to take special care to help prevent crashes:
- Take medicines as prescribed.
- Ask your doctor if you can drive safely.
- Plan to drive when you are least likely to have a
sleep attack or other narcolepsy symptom that could be dangerous while
driving.
- Take naps before driving.
- Stop regularly during a long drive and exercise
during the stops.
- Consider driving with family, friends, or
coworkers or getting rides from them.
Work
People with narcolepsy can work in almost all types
of jobs. It may be best if you have a flexible work schedule so you can take
naps when needed. It also helps to have a job where you interact with your
coworkers. Try to avoid jobs that require you to drive or have long commutes to
work.
The
Americans with Disabilities Act (ADA) protects the employment
rights of people who have disabilities, including narcolepsy. The ADA requires
employers to reasonably accommodate the needs of their workers with
disabilities. For workers with narcolepsy, these accommodations may
include:
- Allowing short naps during the workday
- Adjusting work schedules around sleepy
periods
- Alterations to the workspace or job duties
Workers must tell their employer that they have
narcolepsy to get these accommodations.
Employers with more than 50 workers are also covered
by the Family and Medical Leave Act. This law allows preapproved leave without
pay to care for yourself or a family member with narcolepsy. The Social
Security Disability Insurance or Supplemental Security Income programs may also
help you if you cannot work due to your narcolepsy.
Finding Emotional Support
Sudden sleep attacks or loss of muscle tone can be
embarrassing. This can make you avoid getting together with friends,
schoolmates, or fellow workers, and it can cause low self-esteem. People with
narcolepsy may also feel they have no control over their behavior and may
become depressed. To get emotional support for narcolepsy, you can:
- Work with your doctor to better manage your
symptoms and emotional problems if you have any.
- Change your lifestyle to minimize symptoms.
- Learn about narcolepsy, and tell your family and
friends about the condition.
- Seek professional counseling for yourself and
your family.
- Get involved with patient support groups such as
the
Narcolepsy Network.
School-Aged Children
Narcolepsy symptoms can affect learning by limiting
childrens ability to study, focus, and remember. Children with narcolepsy
are sometimes mistakenly thought to have a learning disability or a seizure
disorder (epilepsy). When tired, some children with narcolepsy tend to
speed up their activities, rather than slow down. These children can be
mistakenly labeled as hyperactive.
You might want to tell your childs teachers
and school administrators about the childs narcolepsy. It is also helpful
to tell the school nurse about the condition and the medicines your child takes
for it. Together you can work out a place to keep the medicines and a schedule
for taking them at school. You also might want to check with student services
about special education and other services, if needed, to help your child with
narcolepsy.
Pregnant Women
If you have narcolepsy and are pregnant or
considering getting pregnant, you should talk to your doctor about the effect
your narcolepsy medicine can have on the baby before and after delivery. You
also might want to discuss with your doctor your chances of having a child with
narcolepsy.
Key Points
- Narcolepsy is a lifelong condition that causes
you to fall asleep suddenly during the day.
- Narcolepsy may cause sudden loss of muscle tone
and control while awake (cataplexy), the inability to move or speak while
falling asleep or waking up (sleep paralysis), and/or vivid dreams while
falling asleep or waking up (hallucinations).
- The symptoms of narcolepsy can cause accidents;
injuries; and problems with learning, working, or connecting with others.
- Narcolepsy tends to develop first between the
ages of 15 and 30.
- The exact causes of narcolepsy are not known.
Many factors probably work together to cause a lack of the brain chemical
hypocretin, which promotes wakefulness.
- A diagnosis of narcolepsy is based on symptoms,
family history of narcolepsy, and the results of sleep tests.
- There is no cure for narcolepsy, but its symptoms
can be relieved with medicines and lifestyle changes.
- Most people with narcolepsy can lead near-normal
lives.
- People with narcolepsy have a number of sources
of support. These include laws that may provide them more flexibility at work
and financial or insurance support, if needed. There are also patient support
groups, such as the
Narcolepsy Network.
Links to Other Information About Narcolepsy
NHLBI Resources
Non-NHLBI Resources
Clinical Trials
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