Facial Paralysis Following Surgery for Acoustic Neuromas

Acoustic neuromas are benign tumors that arise from the vestibular nerves that may secondarily invade the cochlear nerve and impair hearing. These tumors usually push the facial nerve aside.

In most instances the tumor can usually be dissected off the facial nerve. In these cases some facial weakness seen soon after surgery will usually return to normal with time. The degree of facial nerve dysfunction after surgery can not be reliably predicted. Generally the larger the tumor, the greater the chance of facial nerve dysfunction after surgery. On occasion, the tumor can be found to invade the facial nerve. If this is found, our preference has been to leave a small fragment of tumor on the facial nerve. We have not seen growth of these small fragments left on the nerve over time. Perhaps this is because most of the blood supply to the tumor has been lost.

On rare occasions with large tumors, the facial nerve can become disrupted during the course of tumor dissection. The facial nerve can be repaired at the time of surgery, in which case facial nerve recovery would begin 18 months following surgery. Another option is to divert some of the nerve fibers headed for the tongue toward the facial nerve in a separate operation.

It is very important to prevent dryness of the eye. With facial nerve weakness, it might be difficult to completely close the eye leaving the cornea exposed. A feeling as though there is a particle of sand in the eye or redness of the conjunctiva indicates that the cornea is drying. Frequent use of artificial tear drops is a necessity. Lacrilube ointment can be used at nighttime. Occasionally it becomes necessary to implant a small gold weight in the upper eyelid. The weight is heavy enough to allow the eye to close completely but light enough to be able to open the eye and have useful vision. The gold weight can always be removed later once facial nerve recovery occurs.

The role of facial nerve rehabilitation involving exercises and electrical stimulation is controversial. The true efficacy has yet to be determined.