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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