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$Unique_ID{BRK04038}
$Pretitle{}
$Title{Narcolepsy}
$Subject{Narcolepsy Gelineau's Syndrome Paroxysmal Sleep Sleep Epilepsy
Familial Periodic Paralysis Sleep Apnea }
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Copyright (C) 1986, 1988, 1990, 1993 National Organization for Rare
Disorders, Inc.

55:
Narcolepsy

** IMPORTANT **
It is possible that the main title of the article (Narcolepsy) is not the
name you expected.  Please check the SYNONYMS listing to find the alternate
name and disorder subdivisions covered by this article.

Synonyms

     Gelineau's Syndrome
     Paroxysmal Sleep
     Sleep Epilepsy

Information on the following diseases can be found in the Related
Disorders section of this report:

     Familial Periodic Paralysis
     Sleep Apnea

General Discussion

** REMINDER **
The Information contained in the Rare Disease Database is provided for
educational purposes only.  It should not be used for diagnostic or treatment
purposes.  If you wish to obtain more information about this disorder, please
contact your personal physician and/or the agencies listed in the "Resources"
section of this report.


Narcolepsy is a rare disorder characterized by abnormal drowsiness during
the day, sudden extreme muscle weakness (cataplexy), hallucinations,
paralysis while sleeping, and disrupted sleep during the night.

Symptoms

The symptoms of Narcolepsy generally begin between the ages of 10 to 20
years.  The development and severity of symptoms vary greatly from patient to
patient.  The onset of Narcolepsy symptoms initially occurs one at a time;
appearance of new symptoms may be separated by years, and generally do not
appear in any specific order.  Narcolepsy usually begins in an adolescent
whose initial symptoms are mild but become worse with age.  Sometimes
symptoms do not change for months or years, while at other times symptoms may
change very quickly.

Exaggerated daytime drowsiness is usually the first symptom of
Narcolepsy.  People with Narcolepsy usually experience periods of sleepiness,
tiredness, lack of energy, an irresistible urge to sleep ("sleep attack"),
and/or an inability to resist sleep.  This susceptibility to unending
drowsiness and/or falling asleep may occur every day but the severity varies
throughout each day.  The total sleep time for people with Narcolepsy in
every 24 hour period is generally normal because they sleep repeatedly for
short periods during the day and night.

Another symptom of Narcolepsy is the sudden loss of voluntary muscle tone
(cataplexy).  This often occurs during times of intense emotions such as
anger, elation, and/or surprise.  Episodes of cataplexy may occur as short
periods of partial muscle weakness.  Occasionally, there may be an almost
complete loss of muscle control that lasts for several minutes.  This may
result in sudden collapse.  During a cataplectic attack, speech and movement
become difficult or impossible although there is no loss of consciousness.
People experiencing a cataplectic attack generally maintain partial awareness
of their surroundings.  Only some people with Narcolepsy will also have
cataplexy, and cataplexy is not necessary for a diagnosis of Narcolepsy.

Hallucinations are frightening episodes that may occur during the
beginning and/or end of a sleep period (hypnaogic hallucinations) in people
with Narcolepsy.  Hallucinations may pertain to any or all of the senses
(i.e., taste, touch, smell, hearing, and/or vision).  These hallucinations
may be so intense that it may be impossible for the person to distinguish
reality from fantasy.

People with Narcolepsy may experience "sleep paralysis."  During sleep
they may want to move but are unable to do so and as a result may experience
panic.  The occurrence of sleep paralysis typically coincides with falling
asleep or waking up.

People with Narcolepsy may awaken during the night as a result of
nightmares, the urge to urinate, and/or temporary, repeated interruptions of
breathing (sleep apnea).  At times there is no apparent reason for awakening,
and frequently the awakenings are associated with a craving for food,
especially something sweet.  (For more information on Sleep Apnea, see
Related Disorders section of this report.)

Causes

The exact cause of Narcolepsy is not known.  This disorder is known to run in
families and an association with the human leukocyte antigen (HLA-DR2) has
been reported in some cases of Narcolepsy.  HLAs are genetic markers that
have been identified on human chromosome 6.  Scientists suspect that
inheritance of a gene makes a person susceptible to Narcolepsy, but they do
not know the pattern of inheritance and how the gene may be transferred from
one generation to another.

Affected Population

The exact number of people with Narcolepsy in the United States is unknown.
The American Narcolepsy Association has estimated that Narcolepsy affects
approximately 200,000 Americans but other estimates are lower.  Approximately
5 percent of people with Narcolepsy experience symptoms by the age of 10
years; 5 percent of patients have symptoms after the age of 20 years, and 18
percent of people with Narcolepsy develop symptoms after the age of 30 years.
Symptoms rarely begin after the age 40.  Narcolepsy tends to remain a
lifelong condition.  Slightly more males are affected by this disorder than
females.

Related Disorders

Symptoms of the following disorders can be similar to those of Narcolepsy.
Comparisons may be useful for a differential diagnosis:

Symptoms resembling those of Narcolepsy may occur after brain tumors
(intracranial), head trauma, hardening of the arteries in the brain (cerebral
arteriosclerosis), psychosis, and/or excessive amounts of protein in the
blood due to kidney failure (uremia).

Episodes of sudden extreme muscle weakness (cataplexy) may also occur
because of Familial Periodic Paralysis.  This disorder is characterized by
periods of cataplexy that last for prolonged periods of time as compared with
cataplexy associated with Narcolepsy.  Familial Periodic Paralysis is a
result of an inborn error of potassium metabolism that causes abnormally high
levels of this mineral in the blood.

Sleep Apnea is a common sleep disorder characterized by temporary,
recurrent interruptions of breathing during sleep.  Symptoms of the disorder
include wakefulness during the night, excessive sleepiness during the day,
loud snoring, and/or obesity.  In obstructive apnea, the most common form of
Sleep Apnea, labored breathing is interrupted by airway tightening
(constriction).  The muscles of the diaphragm and chest build up sufficient
pressure to force the airway open; partial awakening may then occur and the
person may gasp for air.  Sleep is resumed as breathing begins again.
Untreated Sleep Apnea may be associated with high blood pressure, irregular
heart beats, swelling in the arms and/or legs, hallucinations, anxiety,
and/or irritability.  (For more information on this disorder, choose "Apnea,
Sleep" as your search term in the Rare Disease Database.)

Therapies:  Standard

Diagnosis of Narcolepsy is made through sleep tests which monitor breathing,
brain, and muscle activity throughout all the stages of sleep.  A physician
who is trained in sleep disorders is able to diagnose and treat Narcolepsy.

There are several drugs that may help to control the symptoms of
Narcolepsy.  The medications selected for a particular patient are based on
their symptoms and response to previous therapy.  In some patients,
Narcolepsy may be accompanied by repeated episodes of cataplexy while in
other patients, sleep attacks are the most compelling symptoms.  Those people
who are not seriously hampered by sleep attacks, sleepiness, or cataplexy may
not require drug therapy.

Drugs used to treat people with Narcolepsy who experience sleep attacks
and/or excessive sleepiness may include methamphetamines (such as Desoxyn) or
amphetamines (such as Ritalin, Cylert, Dexedrine, or pemoline).  Side effects
of these drugs may include personality changes (particularly tenseness and
irritability), and depression.  These side effects typically occur in the
late afternoon and evening as the drugs wear off, and/or on weekends when
some individuals tend to reduce their drug dosage.

Methylphenidate (Ritalin) is the preferred drug (a central nervous system
stimulant) for the treatment of sleep attacks and drowsiness.  Ritalin can be
used together with other drugs used to treat cataplexy, whereas some other
medications of this type can produce serious drug interactions.

Drugs used to treat people with Narcolepsy who experience cataplexy include
imipramine (tofranil), desipramine, protriptyline, and chlorimipramine.  Some
people with Narcolepsy may experience drug tolerance leading to a need for
higher dosages which may increase the risks of side effects.  Sudden
withdrawal of these types of medications may result in exaggerated drowsiness,
a dangerously severe depression, and/or a very dramatic increase of
cataplectic symptoms.  Close medical supervision by a physician is necessary
for patients taking these drugs or withdrawing from them.

Sleep habits are important for a person with Narcolepsy.  Assuring
regular bedtime hours and the prevention of sleep interruptions are
important.  Intervals of naps during the day may help to control excessive
daytime sleepiness.  A physician should help the patient in establishing a
sleep schedule that is the most beneficial for the individual.  Those
Narcolepsy patients who also have sleep apnea will benefit from use of a
device called a Continuous Positive Airway Pressure (CPAP).  This medical
device enables the patient to breathe normally during sleep so they are not
deprived of oxygen and can achieve a more normal sleep pattern.

Therapies:  Investigational

The National Institute of Mental Health (NIMH) and the National Institute of
Neurological Disorders and Stroke (NINDS) support research in sleep
disorders, including Narcolepsy.

Gamma-hydroxybutyrate (GHB) is an orphan drug that is being tested in
sleep disorder centers as a treatment for Narcolepsy and cataplexy.  Fewer
episodes of sleep paralysis and hynagogic hallucinations have been reported
in some patients taking this drug.  Preliminary studies indicate that some
patients with Narcolepsy can stop or reduce their use of stimulant
medications while taking gamma-hydroxybutyrate.  The experimental drug is
manufactured by Biocraft Laboratories, P.O. Box CN0200, Elmwood Park, New
Jersey, 07407.

Vitoxazine hydrochloride is another experimental drug currently being
studied, especially for the control of cataplectic symptoms associated with
Narcolepsy.  For further information about this drug contact Stuart
Pharmaceuticals, Division of ICI Americas, Inc., Wilmington, Delaware, 19897.

Scientists are beginning to study human brain tissue from people with
Narcolepsy.  Preliminary reports suggest that the brains of people with
Narcolepsy may have abnormally high numbers of specialized chemical sites
(receptors) in their brain cells that bind to the neurotransmitter dopamine.
These dopamine receptors are located deep within the brain in the basal
ganglia, an area that regulates movement and emotions.  This abnormality of
dopamine receptors may be associated with the fact that emotional extremes
can trigger attacks of cataplexy.  More study of brain tissue is needed to
confirm these findings.  However, since people do not die of Narcolepsy, it
is difficult for scientists to obtain enough postmortem brain tissue for
study.

This disease entry is based upon medical information available through
June 1993.  Since NORD's resources are limited, it is not possible to keep
every entry in the Rare Disease Database completely current and accurate.
Please check with the agencies listed in the Resources section for the most
current information about this disorder.

Resources

For more information on Narcolepsy, please contact:

     National Organization for Rare Disorders (NORD)
     P.O. Box 8923
     New Fairfield, CT  06812-1783
     [phone]

     American Narcolepsy Association, Inc.
     425 California St.
     San Francisco, CA  94104
     [phone]

     Narcolepsy Network
     Box 1365, FDR Station
     New York, NY  10150

     NIH/National Institute of Neurological Disorders & Stroke (NINDS)
     9000 Rockville Pike
     Bethesda, MD  20892
     [phone]
     [phone]

References

MENDELIAN INHERITANCE IN MAN, 10th Ed.:  Victor A. McKusick, Editor:  Johns
Hopkins University Press, 1992.  Pp. 752-753.

CECIL TEXTBOOK OF MEDICINE, 19th Ed.:  James B. Wyngaarden, and Lloyd H.
Smith, Jr., Editors; W.B. Saunders Co., 1990.  Pp. 2065-2066.

BIRTH DEFECTS ENCYCLOPEDIA, Mary Louise Buyse, M.D., Editor-In-Chief;
Blackwell Scientific Publications, 1990.  Pp. 1214-1215.

PRINCIPLES OF NEUROLOGY, 4th Ed.; Raymond D. Adams, M.D. and Maurice
Victor, M.D., Editors; McGraw-Hill Information Services Company, 1989.  Pp.
314-317.

NARCOLEPSY UPDATE.  J.W. Richardson et al.; Mayo Clin Proc (July 1990;
65(7)).  Pp. 991-998.

NARCOLEPSY. M.S. Aldrich; Neurology (July 1992; 42(7 Supp 6)).  Pp. 34-
43.