The severity of Bell's palsy varies. It is usually unilateral— affecting one side of the face, though rarely it may affect both sides. The facial paralysis produced may be temporary or permanent. In a small minority of cases the paralysis appears cured, but recurs. The return attack usually affects the previously-unaffected side of the face. In women who have had Bell's palsy, pregnancy is associated with return attacks. The incidence of Bell’s palsy increases with age, although it can show up at any time, even in children.The exact cause of Bell's palsy is unknown, although it has been linked to a number of causes such as:
The Mayo Clinic has found that 75 percent of those who get Bell’s palsy have an upper respiratory infection first. Bell's palsy usually develops suddenly, over one day. However, there are cases where symptoms take longer to develop— perhaps two to five days.
Symptoms may include:
- a sudden weakness of one or both sides of the face
- drooping of the eyelid and corner of the mouth
- drooling after brushing the teeth or when drinking
- excessive tearing in one eye
- the inability to: wrinkle the brow, close an eyelid, smile, show the teeth, puff the cheeks
- perception of sounds as being unnaturally loud
- pain or a slight discomfort around the jaw and behind the ear
- tearing while chewing
- blinking when trying to smile
- twitching
- nasal obstruction
- ringing in one or both ears
- difficulties in tasting certain foods (loss of taste at the front of the tongue)
Abnormal movement or paralysis of the face can result from other causes, such as infection, injury, stroke, or tumors, and an evaluation is necessary to determine the cause. Diagnosis of Bell’s palsy is usually made clinically in the doctor’s office, but to assess its severity or to prove the diagnosis in some cases, your physician may order blink reflex tests, video, and electromyography, which tests the electrical activity of muscles using fine electrodes.For mild Bell's palsy, physical therapy at home may help in recovery. Such a program includes:
- application of moist heat to reduce pain
- massage with a moisturizer
- facial exercises done while looking in a mirror
Treatments that may be prescribed for severe cases of Bell's palsy include:
- cortisone drugs (steroids), most commonly prednisone
- drug therapy combining acyclovir (anti-viral) with prednisone or other cortisone drugs
- therapy with a hormone called ACTH, to stimulate the body’s own cortisone production
- surgery to relieve pressure on the nerve
- plastic surgery to reduce deformities
A serious complication that happens with Bell's palsy is the inability to close the eyelid, exposing the eye to irritation and drying. The doctor may advise use of eye drops, use of an eye patch, or taping the eye closed to protect the cornea and keep it moist.
About ninety percent of Bell's palsy cases clear up without further treatment in three weeks. The rest of the cases may take up to four months for recovery. A few people may have permanent symptoms of Bell's palsy and may require ongoing evaluation and plastic surgical intervention. In most cases, Bell's palsy cannot be prevented because its exact cause is unknown.
