When the reactivated virus causes inflammation and swelling, the nerve has no room to expand and shuts down. Clinical diagnosis is one of exclusions, especially to rule out stroke or tumors. An MRI scan is helpful. Electrical testing comparing conductivity of facial nerves on both sides of the face can help determine the potential for improvement. If denervation is 90 percent or greater, there's a 50 percent chance the patient will have a bad outcome.
Treatment includes steroids, antivirals and analgesics.
Eye symptoms related to the inability to move the eyelid must be managed. Muscle stimulants and exercise may or may not help. Pred-nisone and acyclovir or one of its analogs are the treatments of choice and produce the best results when begun within three days of symptom onset. Symptoms of Bell s palsy include sagging muscles, weakness on one side of the face and the inability to close one eye. A corner of the mouth may droop, and patients may have trouble retaining saliva.