Bell’s Palsy
What is it?
Bell’s palsy is
an unexplained weakness or paralysis of the facial nerve,
the nerve that controls muscle movement on one side of the
face. The condition causes drooping on the affected side,
and individuals may not be able to close the eye and may
experience tearing, drooling and hypersensitive hearing.
Although Bell's palsy is unsettling and inconvenient, it
is typically not indicative of a serious health problem
and in most cases completely resolves itself.
Who gets it?
About 40,000 to
65,000 Americans are stricken with Bell's palsy each year.
The condition can strike at any age, but young and
middle-age adults seem to be the most vulnerable. Pregnant
women and individuals with diabetes, influenza, a cold, or
an upper respiratory infection seem to be at a greater
risk. About eight percent of patients report a family
history of Bell's palsy, but it's unclear if the disease
has a genetic basis.
What causes
it?
While the exact
cause of Bell’s palsy is not known, many doctors believe
that in most cases it is triggered by and infection of the
facial nerve by herpes simplex virus (HSV), the same virus
that causes cold sores. HSV infection has been discovered
in up to seventy percent of patients diagnosed with Bell’s
palsy. Other diseases including Lyme disease and, rarely,
HIV, may also cause sudden facial paralysis. Varicella-zoster
virus, a related herpes virus and the cause of chickenpox
and shingles, is another cause.
What are the
symptoms?
Symptoms of
Bell’s palsy occur in just a day or two and include a
sagging eyebrow and mouth on the affected side. If facial
paralysis occurs more gradually, the cause of nerve damage
may be another illness, such as cancer. Some people lose
the ability to close one eye and have decreased tearing
and loss of taste on the affected side. Muscle control is
either inadequate or completely missing. Another common
symptom is the ear on the affected side becomes abnormally
sensitive to loud noises. There may also be involuntary
facial twitches that accompany the other symptoms.
How is it
diagnosed?
To diagnose
Bell’s palsy, the doctor will first try to rule out other
causes, since facial paralysis has been linked to several
other conditions such as Lyme disease, ear infections,
meningitis, syphilis, rubella, mumps, chickenpox, and
infectious mononucleosis. Although Bell's palsy is not
life threatening, it can present symptoms similar to truly
serious conditions, such as a stroke, ruptured aneurysm,
or tumors.
During the
initial examine, the doctor may ask a patient about recent
illnesses, accidents, infections and any other symptoms. A
visual exam of the ears, throat, and sinus may be done,
and the hearing may be tested. The doctor may also compare
involuntary movements of the face to voluntary ones. A
neurologic exam may be performed to rule out involvement
of other parts of the nervous system. Blood tests and a
cerebrospinal fluid analysis may be ordered as well to
help determine the presence of a bacterial or viral
infection or an inflammatory disease. Electrophysiological
tests, in which a muscle or nerve is artificially
stimulated, may be used to assess the condition of facial
muscles and the facial nerve. Radiological tests may also
be included, such as an x ray, as well as imaging tests,
such as an MRI, and computed tomography. These tests allow
an excellent view of the nerve itself.
What is the
treatment?
Early treatment
of Bell’s palsy may involve antiviral medications and
corticosteroids to improve the patient’s chances for full
recovery. Antiviral drugs, such as acyclovir, famciclovir,
or valacyclovir, are prescribed to destroy actively
replicating viruses and prevent further damage to the
facial nerve. Corticosteroids, such as prednisone, are
thought to be useful in reducing swelling and relieve
compression on the nerve. If a patient is unable to close
the eye on the affected side of the face, the doctor may
prescribe artificial tears and using an eye patch during
the day to keep the eye moist. At night, the doctor may
recommend the use of eye lubricants or viscous ointments
along with taping the eye shut.
The doctor will
probably recommend further examinations to track recovery.
Most individuals with Bell's palsy begin to notice
improvement in their condition within two to three weeks
of the symptoms' onset. At least eighty percent of them
will be fully recovered within three months. Among the
other twenty percent of afflicted individuals, symptoms
may take longer to resolve or they may be permanent. A
small percentage of patients suffer from permanent facial
deformities and experience permanent problems with spasms,
twitching, or contracted muscles.
Self-care tips
While Bell's
palsy is not preventable, it very rarely occurs twice in
the same person. If the patient experiences facial
paralysis again, another problem is probably causing it.
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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