Everybody has two facial nerves, one on each side of the face that control muscles to make expressions (e.g., smiling, frowning and winking). Facial nerve problems interfere with these processes and can result in weakness or paralysis of the face. This occurs any time the facial nerve fibers become irritated or disrupted. A number of conditions can cause facial paralysis, including infections, fractures and injuries, strokes, tumors, toxins, and disorders such as Lyme disease and Sarcoidosis, but the most common is Bell’s Palsy.
Those most likely to experience facial nerve problems are 40 or older, have diabetes, weakened immune systems, or upper respiratory disorders. Pregnant women are especially susceptible.
How Does the Facial Nerve Work?
The anatomy of the facial nerve is very complex. It passes through the base of the skull in transit from the brain to the muscles responsible for facial expression. After leaving the brain, the facial nerve enters the bone of the ear (temporal bone) through a small bony tube (the internal auditory canal) 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 gland in the face (parotid gland) and divides into many branches, which supply the various facial muscles. The facial nerve branches off in many places as it courses through the temporal bone: to the tear gland, stapes muscle, tongue (for taste sensation), and saliva glands.
Signs of Facial Problems
Symptoms associated with facial problems include any or all of the following:
- Facial weakness or paralysis
- Facial droopiness or swelling
- Twitching facial muscles
- Trouble blinking or closing one eye
- Difficulty speaking, eating and drinking
- Earache
- Drooling
- Sensitivity to sound
Diagnosis and Treatment
Facial nerve problems are diagnosed through a series of tests. These might include:
- A complete review of medical history and current symptoms
- A physical exam, including a look at facial symmetry and movement
- Tear, taste, salivation, and blood tests
- Hearing and balance tests to gauge auditory nerve responses
- Imaging exams such as CT or MRI scans to look for tumors, fractures, or infection
- Electrical exams such as electromyography, electroneuronography, or a nerve excitability test to gauge facial nerve function
Many cases of facial paralysis are temporary and end up resolving on their own, though side effects (muscle spasms and weakness, changes in taste) often linger.
The treatment given will focus on correcting the source of the nerve damage. Infections are treated with antibiotics, while surgery to remove bone in the vicinity of the facial nerve can help correct some abnormalities. Steroids can be given to combat facial swelling, and physical therapy may be prescribed for long-term results.