Doctor, what is
Bell’s Palsy?
Insight into facial nerve disorders
• How does the facial nerve affect facial expression?
• What causes sudden facial paralysis?
• How are facial nerve disorders treated?
• and more...
Disorders of the facial nerve can occur to men, women, and
children, but they are more prominent among men and women
over 40 years of age, people with diabetes, upper
respiratory ailments, weak immune systems, or pregnant
women. Cases of facial paralysis can be permanent or
temporary, but in all circumstances there are treatments
designed to improve facial function.
What is the facial nerve?
The facial nerve resembles a telephone cable and contains
7,000 individual nerve fibers. Each fiber carries electrical
impulses to a specific facial muscle. Information passing
along the fibers of this nerve allows us to laugh, cry,
smile, or frown, hence the name, “the nerve of facial
expression.”
When half or more of these individual nerve fibers are
interrupted, facial weakness occurs. If these nerve fibers
are irritated, then movements of the facial muscles appear
as spasms or twitching. The facial nerve not only carries
nerve impulses to the muscles of the face, but also to the
tear glands, to the saliva glands, and to the muscle of the
stirrup bone in the middle ear (the stapes). It also
transmits taste from the front of the tongue.
Since the function of the facial nerve is so complex, many
symptoms may occur when the fibers of the facial nerve are
disrupted. A disorder of the facial nerve may result in
twitching, weakness, or paralysis of the face, dryness of
the eye or the mouth, or disturbance of taste.
How does the facial nerve affect facial expression?
The facial nerve passes through the base of the skull in
transit from the brain to the muscles that control facial
expressions. After leaving the brain, the facial nerve
enters the temporal bone through the internal auditory
canal, a small bony tube, in very close association with the
hearing and balance nerves. Along its inch-and-a-half course
through a small canal within the temporal bone, the facial
nerve winds around the three middle ear bones, in back of
the eardrum, and then through the mastoid (the bony area
behind the part of the ear that is visible).
After the facial nerve leaves the mastoid, it passes through
the salivary or parotid gland and divides into many
branches. The facial nerve has four components with several
distinct functions: facial expression, taste sensation, skin
sensation, and saliva and tear production.
What causes sudden facial paralysis?
Infections, injuries, or tumors can cause facial nerve
disorders, but the most common cause of facial weakness is
Bell’s palsy. This disorder, which often comes on suddenly
and reaches its peak within 48 hours, is probably due to the
body’s response to a virus. When there is a virus, the
facial nerve within the ear (temporal bone) swells, and this
pressure on the nerve in the bony canal damages it.
The paralysis is likely to affect only one side of the face,
but in rare cases it affects both sides of the face at once.
Bell’s palsy may last from two to three weeks or longer. An
early sign of improvement, such as getting a sense of taste
back, is often a good indication that there will be a
complete recovery.
How are facial nerve disorders treated?
Since otolaryngologists—head and neck surgeons have special
training and experience in managing facial nerve disorders,
they are the most qualified physicians to perform an
in-depth evaluation of abnormal movement or paralysis of the
face. An evaluation will include an examination of the head,
neck, and ears, as well as a series of tests.
Some of the most commonly used tests are:
• Hearing Test—Determines if the cause of damage to the
nerve has involved the hearing nerve, inner ear, or delicate
hearing mechanism.
• Balance Test—Evaluates balance nerve involvement.
• Tear Test—Measures the eye’s ability to produce tears. Eye
drops may be necessary to prevent drying of the surface of
the eye (cornea).
• Imaging CT (computerized tomography) or MRI (magnetic
resonance imaging)—Determines if there is an infection,
tumor, bone fracture, or other abnormality in the area of
the facial nerve.
• Electrical Test—Stimulates the facial nerve to assess how
badly the nerve is damaged. This test may have to be
repeated at frequent intervals to see if the disease is
progressing.
The results of diagnostic testing will determine treatment.
The goal of the treatment is to eliminate the source of the
nerve damage. Patients with less nerve damage have better
chances of recovery. Medications are often used as part of
the treatment:
• If infection is the cause, then an antibiotic to fight
bacteria (as in middle ear infections) or antiviral agents
(to fight syndromes caused by viruses like Ramsay Hunt) may
be used.
• If swelling is believed to be responsible for the facial
nerve disorder, then steroids are often prescribed.
• In certain circumstances, surgical removal of the bone
around the nerve (decompression surgery) may be appropriate.
What treatments are recommended for permanent facial
paralysis?
Patients with a permanent facial paralysis may be
rehabilitated through a variety of procedures including:
• Eyelid weights or springs
• Muscle transfers and nerve substitutions
• A special form of physical therapy called facial
retraining
• Weakening the paralysis by chemical injection
How does the facial nerve affect the health of the eye?
Remember, when the facial nerve is paralyzed, considerable
attention must be given to maintaining a healthy eye through
a constant flow of tears. Tears are spread out over the eye
by blinking. Since blinking is diminished or eliminated when
facial nerve paralysis is present, special care must be
given to prevent drying, erosion, and ulcer formation on the
cornea which may result in possible loss of the eye.
What are the common signs or symptoms?
• Twitching
• Weakness or paralysis of face
• Dryness of the eye or mouth
• Disturbance or loss of taste
• Drooping eyelid or corner of the mouth
• Difficulty in speaking
• Dribbling when drinking or after cleaning teeth
• Ear pain
Tips to help recovery
• Exercise the facial muscles in front of a mirror.
• Massage the face.
• Apply gentle heat to reduce pain.
• Using a finger, regularly close the eye to keep it moist.
• Tape the eye closed for sleeping.
• Use protective glasses or clear eye patches to keep the
eye moist and to keep foreign materials from entering the
eye.
• Use doctor-recommended artificial tears or an ointment to
keep the eye moist.
