Many people worry they have had a stroke when they suddenly experience facial palsy.

Unlike a stroke, which is caused by blocked or ruptured blood vessels in the brain, facial palsy (also known as Bell’s palsy) occurs when the nerves of the face muscles become paralyzed. Most cases have benign progress and resolve spontaneously without any treatment.

Facial palsy usually takes approximately three to four days to develop and can take up to several weeks or months to recover, but most people recover within one year. However, facial palsy sometimes cannot be completely cured and people may be left with some residual effects.

Causes and symptoms

The exact causes of facial palsy are not yet known, but it is thought to be due to neuritis caused by viral infections or autoimmunity. Facial nerve palsy is the most common cranial nerve palsy. A minimum of 3,000 people across the country suffer from it every year. Both men and women of all ages can develop facial palsy; however, it is more common in younger people aged 25-30 years. The rate of recurrence is less than 5 percent and sometimes a family history of facial palsy can be evident.

The condition is characterized by a unilateral paralysis of the face without changes in sensation. Before the onset of paralysis, people commonly experience pain behind the ear. When the symptoms develop, people will have difficulty closing their eyes and as a result when washing their face, soapy water can get into their eye.

The paralyzed side of the eye is dry due to lack of tears and dust can easily enter the eye causing pain. When people smile, the paralyzed side of the mouth will not move and this can typically lead the mouth moving to the opposite side, a common symptom of facial palsy. Loss of taste can also occur, but this improves within a few days. People can also experience loud and ringing sounds. These symptoms are all due to he palsy of the seventh cranial nerve (VII), the facial nerve.

Stroke, facial palsy due to other problems of the central nervous system and Bell’s palsy all show different symptoms. The most obvious difference is that while Bell’s palsy leads to the paralysis of the eye and the mouth, in stroke, the muscles around the mouth are the only areas that show paralysis and the forehead and the eyes are spared.

Although this is not always the same for all people, it plays an important role in distinguishing between Bell’s palsy and a stroke. Although both sides of the face can become paralyzed at the same time, this accounts for less than 1 percent of facial palsy cases.

Sequela and treatment

When people get facial palsy, many tend to seek acupuncture treatment. However, this is not necessary, as facial palsy resolves itself naturally with time.

Acupuncture at present, is not proven to aid the recovery for facial palsy. It is important that people are diagnosed appropriately by the doctor first for assessment of the condition and also to identify its cause.

Electromyography assesses the functioning of the facial nerve in order to diagnose the current state of the paralysis and also evaluates the prognosis of the condition. If other causes are suspected, brain MRI’s are recommended. If a diagnosis of Bell’s palsy is established, the best treatment is for patients to take sufficient rest until recovery.

In most cases, facial palsy resolves naturally. However, in some cases there will be residual effects. If the symptoms are severe, then people can take medications such as steroids or antivirals during the early stages. According to research, the use of pharmacological treatments within 3 weeks of the beginning of facial palsy can improve the recovery rate and minimize residual effects. When severe residual symptoms are expected from the assessment after three weeks of the onset, patients can undergo ENT (ear, nose and throat) surgery, but the success rate from the surgery is hard to predict, so the matter should be carefully decided upon.

Even with the treatment for facial palsy, different residual effects may remain for different people. Some examples of residual effects include: facial muscle weakness due to incomplete recovery, facial muscle spasms worsened during recovery, closing of the eyes when the mouth is opened and tears flowing while eating. These residual effects remain during the recovery phase when the nerves do not recover normally, but instead take on a different neural function.

Currently, the treatment with proven efficacy for facial palsy is eye care. This is because although facial palsy can normally be resolved without treatment, cornea damage can occur in the paralyzed eye. Hence, frequent use of eye drops as well as taking good care of the eyes is essential while recovering from facial palsy.

There are no recommended treatments for the residual effects which will remain for a long time since the beginning of the paralysis. However, if these effects cause significant disability, surgical treatments or injections can be recommended.

Plastic surgery can also be partially effective if people are left with an obvious asymmetrical face or if the face is contorted when smiling or when closing the eyes. The face cannot be completely recovered even after surgery, thus people need to discuss in detail with the surgeon the necessities and the expected outcomes before making the decision to undergo a surgical treatment.

If the patient is suffering from severe spasms on the facial muscles or is enduring difficulties from synkinesis, botulinum toxin injection can be used. This injection works to temporarily paralyze the facial muscles, but the drawbacks of this treatment are the high cost and requirement to repeat the injections every 3-6 months.

Some patients experience stiffness of the face or are conscious about the way their face looks long after recovering from facial paralysis. In these cases, it is recommended that they see a neurologist or a psychiatrist for a consultation and to work out a treatment plan.

By Kim Byoung-joon

The author is a professor at Department of Neurology of Sungkyunkwan University school of Medicine and doctor at Samsung Medical Center. ― Ed.