Dr. Jeff Hersh: Bell's palsy is usually temporary
Q: I'm 70 years old and have had Bell's palsy for three months and still can't blink my eye. Is there anything that I can do to get over this?
A: Bell's palsy is named after Sir Charles Bell, who first described the condition in 1821. It is an acute partial or complete paralysis of the face due to dysfunction of the facial nerve. Although the exact cause is unknown, swelling and inflammation of the facial nerve due to a viral infection is the likely cause. Herpes simplex (the virus that causes cold sores) is the most likely culprit, although other viruses may be involved in some cases.
The anatomy and function of the facial nerve helps explain the symptoms of Bell's palsy. Signals from the left side of the brain make their way to the right facial nerve (and vice versa), which is the major pathway conducting nerve impulses that control the muscles of the right side of the face, taste sensation from the back two-thirds of the right side of the tongue, some aspects of hearing from the right ear and other functions. However, due to an interesting quirk in the wiring of the body, both sides of brain control both sides of the forehead. Therefore, facial paralysis from Bell's palsy will cause partial or complete loss of motor function on the right side of the face including the forehead, in contrast to a stroke where the face may be paralyzed but the forehead is, in general, spared.
The symptoms of Bell's palsy include limited ability to close/blink the affected eye, inability to close the mouth all the way/drooling, and an asymmetric face (including the forehead). Increased sensitivity to sound, loss of taste sensation, pain behind the ear or in the jaw, as well as other less common symptoms can also occur. In less than 1 percent of cases, both facial nerves are involved so both sides of the face are affected.
Bell's palsy is common -- affecting 1 in 5,000 people per year -- and 1 in every 65 people in their lifetime. It is more common in diabetics, late in pregnancy or soon after delivery, and in those of Japanese origin. It can occur at any age but is less common before age 15 or after age 65.
A careful history and physical examination is all that is needed to diagnose Bell's palsy. Other causes of facial paralysis -- such as Lyme disease, other infections, sarcoidosis, Sjogren's syndrome, tumors and other conditions -- must be ruled out. If one of these is suspected, blood tests or X-rays (CAT scan or MRI) may be needed.
Most cases of Bell's palsy would get better without any treatment; however treatment with steroid medications (to decrease the inflammation) can hasten the recovery and improve the chances of a complete recovery. Although it seems logical to use anti-viral medications (due to the presumed viral cause of the inflammation), studies have not shown additional benefit from these.
Preventing the unblinking eye from drying out or being injured is crucial. This requires frequent moisturizing eye drops, lubricating ointment and eye patching for sleep, as well as an eye guard (or glasses) to prevent trauma.
Physical therapy to prevent facial muscle contracture, as well as other supportive treatment, should be used as needed. In certain cases, specialists may recommend surgery or other interventions.
The overall prognosis for Bell's palsy is good; more than 70 percent have a complete recovery (usually within weeks to months) and 15 percent have only slight residual paralysis. Milder initial symptoms are a good prognostic indicator. However, about 10 percent of patients have significant residual symptoms. About 10 percent of patients have a subsequent recurrence of their Bell's palsy (it can be on the same side or the opposite side), with the same overall good prognosis for these recurrences.
Vision loss or other complications occasionally occur from the eye drying out or from eye trauma. Imperfect healing/regeneration of the facial nerve can lead to abnormal residual function, such as "crocodile tears" (where the patient tears while eating due to cross innervation of the tear reflex).
For patients that do not have at least some improvement three to six months after they develop Bell's palsy, re-evaluation by a specialist and consideration of other causes of the facial paralysis should be considered.
Jeff Hersh, Ph.D., M.D., F.A.A.P., F.A.C.P., F.A.A.E.P., can be reached at DrHersh@juno.com.