Narcolepsy
is a malfunction of the sleep/wake regulating system in the brain
of unknown origin. Its most common manifestation is an irresistible
tendency to fall asleep, even in unlikely circumstances such as
in the middle of a conversation or at a meal. These sleep
attacks are brief periods of sleep during the person's normal
waking. In order for narcolepsy to be diagnosed, a person must
have suffered from the sleep attacks for at least three months.
The diagnostic criteria is as follows:
Each day for 3 months or more the patient has had irresistible
attacks of refreshing sleep.
The person experiences either or both of:
Cataplexy
(sudden, brief loss of muscle tone bilaterally, usually associated
with intense emotion) Intrusions of REM sleep into transitions
between waking and sleeping, as shown by
either of:
Hypnagogic or hypnopompic hallucinations or Sleep paralysis
at the beginning or end of sleep.
These symptoms are not directly caused by a general medical condition
or substance use, including medications and drugs of abuse.
Differential
Diagnosis:
Some disorders have similar or even the same symptoms. The clinician,
therefore, in his/her diagnostic attempt, has to differentiate
against the following disorders which need to be ruled out to
establish a precise diagnosis.
Cause:
Narcolepsy
can occur in people of both sexes. Symptoms, particularly sleepiness
usually begin in late childhood, the teen years or the early twenties.
Narcolepsy can begin after the age of 30: but such is relatively
uncommon. In contrast, while sleep apnea can develop in childhood,
it more often becomes a significant and progressive problem later
in life.
The
usual cause appears to be a problem with the chemical neurotransmitters
that regulate communications between different groups of nerve
cells in the brain. Only rare cases have been reported of narcolepsy
arising as the consequence of such structural causes as brain
tumors, brain infections and head injuries. CT/MRI scans of the
brain are normal in the vast majority of cases.
Narcolepsy
can run in families such that some individuals appear genetically
predisposed to develop it. Its onset sometimes follows stressful
events, but such does not indicate that it is a psychological
disorder. In fact, some breeds of dogs develop narcolepsy on a
genetic basis.
Treatment:
Narcolepsy
may be complicated by emotional or physical problems therefore
treatment my have to involve a multi-discipline approach.
There is no
known cure for narcolepsy and treatment therefore is aimed at
control of the symptoms.
Lifestyle
adjustments and learning to cope with the emotional and other
effects of the disorder may improve functioning in work and social
activities. Planned naps and sleeping may help to regulate daytime
sleep and reduce the number of unplanned, sudden sleep attacks.
Pharmacotherapy
[ See
Psychopharmacology Section ] :
Prescription
medications may be required for some persons, including stimulants
. Antidepressant medications such as may be helpful in reducing
episodes of cataplexy but usually do not reduce the number of
sleeping episodes.
Stimulants:
Dextroamphetamine (Dexedrine).
Methylphenidate (Ritalin).
Pemoline (Cylert).
Antidepressants:
Imipramine (Janimine, Tofranil).
Protriptyline (Vivactile)
