Peripheral Facial Palsy (Bell's palsy)

What is Bell’s palsy?

Bell's palsy is a dysfunction that causes edema or inflammation of the facial nerve (VII peripheral cranial nerve, responsible for controlling the movement of the muscles of the face), commonly caused by a viral infection.

Bell's palsy was described for the first time by Sir Charles Bell, a Scottish surgeon, who was dedicated to the study the anatomy and physiology of the nervous system using electricity, and established the difference between the motor and sensitive nerves.

What are the symptoms of Bell’s Palsy?

 

Symptoms may appear with rapid onset (usually within hours) of weakness or palsy on one side of the face, facial droop (usually the eye and the side of the mouth), pain around the jaw or behind the ear of the affected side, Tinnitus (a buzz in the ear), dizziness, increased sansitivity to sound on the affected side, headache, decrease in the ability to taste, difficulty drinking or eating, and decrease of the usual production of saliva and tears forming in the eye on the affected side.

It is extremely important that you seek immediate medical attention because these symptoms can also be seen in a stroke, although Bell's palsy should not be mistaken for a stroke. Also, it is necessary to assess the cause of the paralysis and the severity of illness.

As mentioned before, the most common cause for Bell's palsy seems to be a viral infection, normally related to Herpes simplex (which also causes cold sores), Herpes zoster (causes chickenpox) and Epstein Barr virus (causes mononucleosis).

Risk Factors

The most important risk factors in developing Bell's palsy include a recent upper airway infection, diabetes, chronic ear infection, high blood pressure, Lyme disease, tumors and some say pregnancy (especially during the first trimester).

How to determine the proper diagnosis?

The diagnosis will be based on the symptoms and by looking at the face trying to asses which muscles are affected. If your diagnosis is still in question, your doctor may need to run some other tests, including an Electromyography (EMG) which can confirm the presence of nerve damage and determine its severity. A magnetic resonance imaging (MRI) scan or computerized tomography (CT) scan may be needed on occasion to eliminate other possible sources of pressure on the facial nerve, such as an infection, tumor or skull fracture.

Treatment for Bell’s palsy

The treatment of choice involves 2 drugs, corticosteroids and antiviral medication. Although there are certain controversies regarding the effectiveness of the combination, some clinical studies show that corticosteroids are most effective in the treatment of Bell's palsy due to their anti-inflammatory power, especially when administered during the first 72 hours of the onset of the disease.

The antiviral medication can be administered when a variant of the facial paralysis appears, Ramsay-hunt syndrome, associated to Herpes zoster which can affect the external ear canal and/or the tympanic membrane (ear drum). It may present with hypoacusia (diminished hearing), tinnitus and vertigo.

Also, this medication may be combined with physical therapy to help speed the recovery of the patient.

Surgery is almost never recommended to relieve the pressure of the facial nerve as this is controversial and almost is never undertaken.

It´s very important to understand that, after the apparition of the paralysis of the facial muscles, the sooner you present yourself to your doctor to get a treatment, the better chances you have of recovering up to 90% or greater of the movement of your face. After the first 72 hours, the possibilities of a total recovery diminish. So, go to your doctor as soon as possible!