Disorders of the Facial Nerve
The Facial nerve can be affected by infections, tumors and injuries. One of the most common causes of Facial nerve dysfunction is Bell's palsy. Though the cause of this is still not certain, research is pointing to infection by herpes simplex virus type 1 as a likely source. Infection by the virus causes the nerve to swell, and become "choked" within its canal in the skull base. Chronic ear infections such as otitis media can also cause nerve disorders; benign tumors such as cholesteatomas or Facial nerve schwannomas can also occur. Injuries to the facial nerve can occur by trauma such as motor vehicle accidents or assault, or as the result of surgery when part of the nerve must be resected.
Often the cause of Facial nerve dysfunction is obvious - trauma, or a known medical condition. When this is not the case, a detailed investigation is necessary. This may include high-resolution magnetic resonance imaging (MRI) and computerized tomography (CT). Electrophysiologic testing such as electroneuronography (ENoG) and electromyography (EMG) may also be performed to further investigate the functional capacity of the nerve and to help determine the prognosis for recovery.
In cases of traumatic nerve damage, an attempt at repair is undertaken. This may require microsurgery for small branches in the face. If the damage is within the skull, however, a more complex procedure may be required with microscopic decompression of the nerve (removing the bone that encases the nerve). Surgery to decompress the nerve may also be required when the nerve is damaged by an infection. In this case, medicine for the viral or bacterial infection is also given, along with steroids. Occasionally patients will seek help after an illness from which the nerve has recovered only partially or not at all. In this setting, we undertake procedures to correct the problem surgically. These options include operations to improve closure of the upper eyelid; to restore the lower eyelid to its proper position and function (lateral transorbital canthoplexy); brow or full facelifting; facial suspension surgery; or re-innervation either by crossover grafting to another cranial nerve or to the opposite facial nerve. This surgery is then followed up with intense rehabilitation and monitoring.
The prognosis for recovery of normal facial nerve function depends on the type and severity of the disorder. We have made great strides recently in our ability to restore function of the nerve. Furthermore, for those
patients whose nerve does not fully recover, we now have a large armamentarium of procedures to rehabilitate the face to return patients to the lifestyle they enjoyed before their illness. The treatment and rehabilitation of facial nerve disorders is complex, and requires the participation of several specialties. We, at UCSD, have a comprehensive program for the diagnosis and treatment of these problems. Our team includes experts in neurosurgery, skull base surgery, neurology and facial plastic and reconstructive surgery who are dedicated to the care of patients with these problems, as well as research in the prevention and treatment of facial nerve dysfunction.