What is Bell’s palsy?
Bell’s palsy is the paralysis of the facial muscles on one side of the face, often caused by a viral infection of the facial nerve. It can also occur when the facial nerve is swollen or compressed.
The facial nerve supplies the facial muscles and therefore if this nerve is damaged, the corresponding side it supplies to will be paralysed. Therefore you may have difficulty in closing the eye on the affected side or difficulty smiling. The nerve damage may also affect the taste sensation and saliva and tear production.
Bell’s palsy occurs all of a sudden and usually gets better within a few weeks on its own. Bell’s palsy can occur in anyone but it tends to be more common among the people aged between 16 and 60 years.
Although Bell’s palsy may present in a similar way, it is important to note that Bell’s palsy is not a result of a stroke or a transient ischaemic attack.
What causes Bell’s palsy?
Even though the exact cause of Bell’s palsy is not known, many doctors believe that this condition is a result of a viral infection, especially Herpes simplex infection of the facial nerve. However, there are other viruses that may cause Bell’s palsy such as:
- Human Immunodeficiency virus (HIV)
- Herpes zoster virus
- Epstein Barr virus
In most of these cases, the facial nerve supplying the affected side of the face shows signs of inflammation such as swelling of the nerve and this damage the nerve.
Who is at risk of developing Bell’s palsy?
One is at a high risk of developing Bell’s palsy if they are:
- Having diabetes mellitus
- Having a family history of Bell’s palsy
- Having an infection of the lungs.
What are the signs and symptoms of Bell’s palsy?
The signs and symptoms of Bell’s palsy are of sudden onset. You may notice it when you wake up in the morning or while you’re trying to eat or drink. Often, many patients diagnosed with Bell’s palsy, give a two to three week history of a cold, ear or eye infection.
The characteristic appearance of a patient with Bell’s palsy is droopiness of one side of the face associated with the inability to open or close the eye on the affected side. Rarely, there have been some cases of Bell’s palsy where both sides of the face are affected.
The other signs and symptoms of Bell’s palsy include:
- Facial weakness
- Drooling of saliva
- Inability to smile or frown
- Difficulty eating and drinking
- Dry eye and mouth
- Lost or altered taste on the tongue
- Pain behind the ear is a common feature seen at the onset of this condition.
- Numbness of the affected side of the face
- Increase in sensitivity to sound (Hyperacusis)
How can Bell’s palsy be diagnosed?
Diagnosis of Bell’s palsy is made on clinical grounds and usually investigations are not required.
When you first visit your doctor with the above mentioned signs and symptoms, he or she will first take a detailed history form you including the symptoms you noticed and when you first noticed them.
Next, a complete examination will be carried out to get an idea of the extent of weakness of the facial muscles. Your ears and the palate will be examined for vesicles or hearing loss.
Although investigations are not necessary to make a diagnosis, sometimes your doctor may order some tests to find out the cause for this condition. Some of the investigations he or she may order include blood tests to exclude bacterial or viral infections, MRI or CT scan to check the nerves in your face.
What is the treatment for Bell’s palsy?
Most cases of Bell’s palsy do not need treatment as it goes away on its own. However, it takes several weeks to months for the facial muscles to return to its normal state. Nearly 85% of the cases recover completely, or almost completely, over 4 to 12 weeks without specific treatment.
However the following medicine can be given to hasten the recovery:
- Corticosteroid drugs to reduce the inflammation. However, this treatment is proven to increase the outcome if it is started within the first 72 hours of onset.
- Pain medications such as Acetaminophen or Ibuprofen which relieves the pain. These medications can be bought over the counter.
- If the Bell’s palsy was a result of a viral infection, then anti-viral treatment should be taken. However, the latest evidence does not support the use of anti-viral agents.
- Your eyes are more likely to be dry therefore eye drops can be used.
In addition to the above medications, you can also undergo physiotherapy to improve the strength of the facial muscles and hasten the recovery process. The physiotherapist will teach you some facial exercises improve the strength of the muscles as well as to help you recover very quickly. Simple facial exercises such as tightening and relaxing the muscles of the face has a great benefit.
Inability to blink in severe facial weakness results in continuous exposure of the cornea to the outside environment thus it may lead to inflammation of the cornea of the eye, a condition known as exposure keratitis. Therefore using an eye lubricating ointment is required and tape the eyes closed carefully at night. Ophthalmological assessment may be needed in more severe cases of Bell’s palsy where you are completely unable to close the affected eye.
Just as eye care is important, mouth care is also important because in Bell’s palsy, there is reduced salivation and food tends to get stuck inside leading to gum disease and tooth decay. Therefore to prevent such problems, it is important that you brush and floss your teeth. Eating slowly and chewing the food properly will also help you to avoid any swallowing problems that you may encounter.
In the group of patients who do not recover, plastic surgery may be helpful. In very rare cases, Bell’s palsy recurs. If it does, an alternative cause for this recurrence should be searched.