A paralyzed face can be disfiguring and can cause functional problems such as drooling and eye infections.

The facial nerve is the most commonly paralyzed nerve of the body. The reason is that the facial nerve is covered in a tight shell of bone. Anything that can cause swelling of the nerve can block off its blood supply. If the blood supply stays choked for a long enough time, the facial paralysis may be permanent.

This is analogous to waking up at night and finding that your arm has gone to sleep. What has happened is that by lying on your arm for an hour or more, the blood supply of the nerves gets cut off. This results in numbness and weakness. But before the numbness becomes complete, tingling in your arm usually wakes you up. By getting off your arm and relieving pressure, the nerves can quickly return to normal. If for some reason, however, you did not relieve the pressure on your arm, the loss of blood supply to your nerves could result in a permanent paralysis. Whether or not this paralysis is permanent, partial or total depends on how much pressure there is and for how long.

Another analogy to facial palsy is your lawn. If you quickly step over the grass, the blades of grass bounce right back. If you leave a heavy box on the lawn overnight, the grass may turn yellow but may green up again in a few weeks. But if you were to leave that box on the lawn for a few days, the blades of grass may wither down to the root

I'd like to review some of the anatomy of the facial nerve and ear to give a better understanding of facial palsies and how they are treated.

Anatomy and Physiology

There are two parts of hearing: mechanical and electrical. The mechanical part picks up sound from the outer ear canal and then vibrates the ear drum and three tiny hearing bones in the middle ear.

The inner ear looks a bit like a snail. It has two halves which are connected and are filled with fluid.

The coil or cochlea takes care of the nerve-part of hearing. Like a telephone, it takes the vibration and turns it into an electric signal that is relayed to the brain.

The other half of the inner ear is the balance or vestibular system. There are three balance canals, each set in a different direction.

In close association to the ear is the facial nerve. It helps move the face and also provides some of the taste fibers to the tip of the tongue. The facial nerve is covered in a rock-hard canal of bone. This unyielding channel is the reason why the nerve can strangle off its own blood supply if it becomes swollen from infection or injury.

The facial nerve also has tiny branches that control taste and tearing.

At the deepest level is the brain from where the hearing, balance and facial nerves originate.

Facial Palsy

Many patients refer to any facial paralysis as a Bell's palsy. Medically, however, this term is reserved only for sudden facial weakness that is most likely caused by a herpes simplex virus. This is the same virus that causes cold sores. We don't know why it sometimes infects the facial nerve, but fortunately this cause of facial palsy has an excellent chance for complete recovery in 9 out of 10 patients. The problem is trying to identify who may be one of the 10% of patients who will not recover well on their own and then to choose the best treatment to avoid a permanently disfigured face.

Rarely, facial paralysis may occur not just once but recur over and over again.

Patients with recurring facial palsy may recover normally the first time or two they develop apalsy. However, each time it recurs, the chances for recovery get worse and worse. These patients need to have a scan to assure that the palsy is not coming from an underlying tumor.

Some patients may develop facial palsy from a much more severe virus called herpes zoster. This is the same virus that can cause shiungles or chicken pox.

The chances for recovering normal facial function are much worse with this type of infection which may also cause deafness, dizziness and ringing of the ears (tinnitus).

Another cause of facial palsy is head injury. After a blow to the head the nerve may swell or it may be crushed if the bone becomes fractured. If this occurs, the surgeon may have to either repair the nerve or relieve pressure from it (decompress it).

Other causes of facial palsy include tumors, infections and surgery. These may require tests such as a MRI or CAT scan.

Deciding on a therapy

Decompression

The goal of treating most types of facial palsy is to reduce nerve swelling.

For Bell's palsy, we currently use steroids and an antiviral medication called Zovirax. These medications appear to provide the best chance of recovery. As with any medication, there may side-effects which you should discuss with your doctor. Steroids taken for months or years will almost alsways cause some side-effects. When taken for only acouple weeks, however, the risks are low.

Some common problems include acid indigestion and insomnia. If you have diabetes or high blood pressure, these illnesses can may get worse while you are on the steroid.

Medications may not always be sufficient. In that case, we need to determine if surgery is indicated to uncap the swollen nerve - an operation called decompression. Surgery is strongly considered especially if electrical testing of the nerve shows that it is withering away.

The goal then is to operate before the nerve has withered down to its root within the brainstem. The longer the decision is delayed, the more the nerve may degenerate and then any possible benefit from surgery will be reduced. It would be like waiting weeks to release pressure from your arm - by then it may be too late. Nonetheless, in most cases, we do not operate immediately because we want to give the nerve at least a few days chance to see if it will recover with medications or time alone. The more the nerve has degenerated, the longer the recovery will be even with surgery.

Gold Weight

In addition to considering whether or not to decompress the nerve, it is important to pay careful attention to the eye. If eye drops do not provide enough lubrication to the cornea, infection and visual loss may develop.

Therefore, we sometimes implant a tiny gold bar just beneath the eyelid skin.

This takes only a few minutes to perform as an outpatient procedure under a local anesthetic. The gold weight can be easily removed in the future if facial function recovers.

Reanimation

For some patients, a timely decompression of the nerve may not be practical or possible. Under these circumstances, there remains the possibility of doing a late repair of an injured nerve or of using other muscles and nerves to try and act as a substitute. Examples include using part of your chewing muscle or tongue nerve. These never create a perfect face but can provide a substantial improvement for people who may have had a paralyzed face for years or even decades.

Risks

Any surgery in or around the ear can put at risk many of the structures that reside in this area. Therefore, risks typically include hearing loss, tinnitus, dizziness, infection and persistent face weakness. Because the facial nerve also controls taste, loss of taste along one side of the tongue is expected. Like facial movement, it may return in time.

Because the narrowest part of the facial nerve canal is located between the inner ear and brain, decompression surgery is performed by working beneath the temporal lobe of the brain. Therefore, risks to the brain are possible although they have been extremely rare in our own hands. Because the facial nerve is covered in spinal fluid, a muscle graft is necessary at the end of the surgery to reduce the chance of a spinal fluid leak. Should this occur, a spinal drain or additional surgery to seal the area may be required.

Infections are minimized by using powerful antibiotics on the day of surgery as a preventative

At the Michigan Ear Institute, doctors perform ear surgery exclusively. This experience and the use of computers to monitor nerves during surgery help to keep our complication rate extremely low.

Postop Expectations and Precautions

The incision around the ear is closed with nonabsorbable stitches which need to be removed in about three weeks. Keep it dry for a week by covering it with a washcloth during showers. Pat it dry or use a hair dryer if it gets wet. Hair will have been shaved around the incision.

Avoid hard nose blowing and heavy lifting to avoid leakage of spinal fluid.

Stuffiness and hearing loss can be expected. This often improve slowly as your body absorbs the healing fluids. In the meantime you can expect to hear inner ear noises and your own heartbeat.

Dizziness is not uncommon after this type of surgery. Be sure to ask your doctor how soon you may return to work or driving.

Conclusion

Facial paralysis can be a frightening and disfiguring problem.

Hopefully, this presentation has made the topic a bit more understandable.

Be sure to discuss any details in greater length with your own doctor.