Bell’s palsy, also known as facial palsy, is a condition that causes sudden and temporary weakness or paralysis of the facial muscles, which results in an inability to control the muscles on the affected side of the face. The affected side of the face droops or becomes stiff. The affected person’s smile is one-sided, and the eyelids on that side resist closing.
The exact cause is still unknown, but it is said to be caused due to some injury or swelling or inflammation of the 7th cranial nerve (facial nerve). Sometimes, it occurs as a result of some reaction to a viral infection. It can happen to anyone at any age, and most of the time, it is temporary. There is no gender or racial preference. It can occur at any age, but more cases are seen in mid and late life with the median age of onset at 40 years.
The symptoms start to decline after a few weeks, and complete recovery takes about six months. Bell’s palsy resolves completely without treatment in about 71% of cases with a recurrence rate of 12%. Treatment with corticosteroids has been found to increase the likelihood of improved nerve recovery.
What Causes Bell’s Palsy?
The exact cause is still unknown, but the incidence of Bell’s palsy is related to exposure to a viral infection, which causes inflammation of the facial nerve. The facial nerve passes through a narrow bony canal on its way to the face, so when it gets swollen, it affects the functioning of the facial muscles. Infections that are believed to cause it are:
- Herpes simplex, which causes cold sore and genital herpes.
- Herpes zoster virus that causes chickenpox and shingles.
- Epstein-Barr virus, which is the cause of infectious mononucleosis.
- Infection caused by cytomegalovirus.
- HIV (human immunodeficiency virus).
- Rubella (German measles).
- Coxsackievirus (hand-foot-and-mouth disease).
Common Symptoms of Bell’s Palsy
Some of the signs and symptoms of Bell’s palsy are as follows:
- Sudden weakness or paralysis on one side of the face.
- Difficulty making facial expressions on the affected side, like closing the eyelids or smiling or frowning.
- Facial muscles twitching.
- Decreased sensation of taste.
- The ear on the affected side becomes more sensitive to sound.
- Reduced tears and saliva production.
- Occasional facial numbness.
Usually, the nerve on one side of the face is affected, but in sporadic cases, nerves on both sides are affected, which cause bilateral symptoms. And sometimes, Bell’s palsy can recur.
What are the Risk Factors?
Bell’s palsy can affect people of any age and gender. It has been noted that the people with the following conditions are more susceptible:
- Diabetic patients.
- Pregnant women, especially during the third trimester and a week after delivery.
- People suffering from an infection of the upper respiratory tract, like cold and flu.
- And people suffering from any viral infection.
- People with a family history of this condition.
Common Complications of Bell’s Palsy
Generally, the symptoms caused due to Bell’s palsy begin to fade after a couple of weeks, and a person recovers fully within six months. But sometimes, severe cases of total paralysis cause the following complications:
- The facial nerve gets damaged irreversibly.
- Synkinesis — It is the involuntary contraction of muscles when you are trying to move some other muscles. This is caused due to abnormal re-growth of the nerve fibers. For example, when the person tries to smile, the eye in the affected side close on its own.
- Because of the inability to close the eyelids, the eye becomes dry. Partial or complete blindness results due to this dryness and scratching of the cornea.
How Bell’s Palsy Diagnosed?
There are no confirmatory or diagnostic tests which can tell you for sure if you have Bell’s palsy. Your doctor, through various physical examination, will determine if you have facial palsy only after he or she has ruled out all the other possible conditions that can cause these symptoms like a brain tumor, stroke, Ramsay Hunt syndrome, myasthenia gravis, and Lyme disease. The doctor will look at the face, and tell the patient to perform various facial movements. They ask the patient to blink, smile, whistle, lift the eyebrows, and frown.
Other tests like magnetic resonance imaging (MRI) and computerized tomography (CT) can be used to rule out any pressure caused due to a tumor or skull fracture impinging on the facial nerve. Nerve conduction study (NCS) is used to confirm the presence of nerve damage and its severity.
What are the Treatment Options?
- Medications — Anti-inflammatory medicine like corticosteroids (Prednisone) are prescribed. This brings down the swelling of the facial nerve. Antiviral drugs like Valacyclovir is also prescribed, but its role in the treatment of Bell’s palsy is still not clear. As the eyelids resist closing, use lubricating eye drops to keep the eyes from getting dry. Wear protective glasses or an eye patch to protect the affected eye. Painkillers are prescribed to relieve pain.
- Physical Therapy — To prevent the paralyzed muscle from shrinking, a physical therapist teaches massages and exercises of the facial muscles. This may also include electrostimulation of facial nerve, however, the results of this procedure are unclear.
- Surgery — In very rare and severe cases, decompression surgery is done to relieve the pressure on the facial nerve.
If you notice any signs of Bell’s palsy, get medical attention immediately as it can also be a sign of stroke. Ones a physician diagnosis it as Bell’s palsy, you can opt for home remedies and physical therapy to ease the symptoms. All the symptoms caused by Bell’s palsy are mostly temporary, and the recovery time varies depending on the severity of nerve damage. The prognosis is good if treatment is started as soon as any symptom develops.
How to Differentiate Bell’s Palsy from a Stroke?
If you experience paralysis (loss of sensation), seek medical attention immediately, as it can be a sign of stroke. Bell’s palsy causes similar symptoms to a stroke, so it is crucial to differentiate between the two. If your facial paralysis is due to a stroke, it will also affect the arms or legs of that side.
The key physical exam finding is a partial or complete weakness of the forehead. If forehead strength is preserved, a central cause such as stroke should be investigated. Findings of double vision, imbalance while walking, swallowing difficulty, slurred speech, and numbness or weakness on one side of the body will indicate an underlying stroke.
Last reviewed at: 25.Jan.2019
Originally published at www.icliniq.com on January 25, 2019.
