Facial nerve paralysis is paralysis of areas of the face innervated by the facial nerve, which may also be referred to as the seventh cranial nerve. This particular nerve winds a long path over the face, and many different areas of the face can be involved. In addition to being associated with paralysis in the face, facial nerve paralysis can also lead to problems with taste, hearing, and vision. There are a number of potential causes of this condition.
Symptoms of facial nerve palsy vary, depending on which areas of the nerve are involved. Changes in the facial expression are common, with the person having trouble smiling and making other expressions on the side of the face which is involved. The sense of taste may be impaired, and the patient may have decreased saliva production. Sensitivity to noise is another sign, as is dryness in one of the eyes.
It is important to distinguish between paralysis and paresis. Facial nerve paralysis requires damage to the nerve so complete that movement is not possible. Facial nerve paresis involves damage which weakens the face, but does not paralyze it. Patients can also experience symptoms such as uncontrollable twitching and other tics in the face as a result of damage to the facial nerve. Bell's palsy is probably the most well known (and common) form of facial nerve paralysis.
Some causes of facial nerve paralysis include trauma to the seventh cranial nerve, which may happen as a result of surgery, a blow, or an accident, along with tumors which impinge on the nerve, certain infectious diseases, and congenital conditions. If the paralysis is congenital, it will be diagnosed soon after birth when the baby is evaluated by a pediatrician.
A doctor can perform a number of tests to assess a patient for facial nerve paralysis. These tests can include taste and hearing tests, testing of saliva production, and electrical tests on the nerves of the face to see if they can conduct electrical signals. Testing can also include balance tests and other tests to assess neurological function.
Facial nerve paralysis can be accompanied by serious complications. Ulceration of the cornea can happen as a result of reduced tear production, for example, and patients may have trouble swallowing or experience a decline in quality of life due to impaired taste. Treatment for this condition is focused on compensating for issues caused by the paralysis, such as using artificial tears to keep the eye lubricated. If the cause is treatable, as might be the case with a tumor, it will also be addressed, hopefully resolving the paralysis.