Bell's palsy, also known as one sided facial paralysis,is caused by
the dysfunction of the facial nerve (7th Cranial Nerve). One pair of
facial nerves, one facial nerve on each side of the face supply the
muscles of face. This condition causes the affected side of the face to
droop.This happens because of the inability of nerve to conduct impulse
to the muscles. This condition comes on suddenly, often overnight, so it
is acute in onset.
It is one of the most common disorder of the cranial nerves. It is also the number one cause of facial paralysis worldwide.
It
affects men and women equally. Although it can occur at any age it is
usually seen in people above the age of 60. People with diabetes have
higher risks of developing this disease.
Cause of Bell's Palsy
Bell's
palsy occurs when the facial nerve fails to stimulate the facial
muscles. This happens when the facial nerve is inflamed or compressed.
This inflammation or compression of the nerve results in paralysis of
the corresponding side of the face. What causes the inflammation of the
facial nerve, is currently unknown. This inflammation can be caused by
anything ranging from trauma or infection from various viruses.
Viruses that have been linked are the virus that causes:
1. Cold sores and genital herpes (herpes simplex)
2. Chickenpox and shingles (herpes zoster)
3. Mononucleosis (Epstein-Barr)
2. Chickenpox and shingles (herpes zoster)
3. Mononucleosis (Epstein-Barr)
Symptoms of Bell's Palsy
The
most common feature of Bell's palsy is the drooping of the affected
side of the face, due to the malfunction of the facial nerve. The
symptoms come on suddenly. These are:
- Rapid onset of mild weakness to total paralysis on one side of patients the face.
- Facial tingling.
- Drooling from the corner of the mouth.
- Disappearance of the wrinkles on the affected side.
- Expressionlessness on the affected side.
- Impaired speech.
In rare cases, it can affect the nerves on both sides of the face.
Diagnosis
There
are no specific tests for Bell's palsy. It is normally diagnosed by a
careful and through elimination of all the other diseases causing the
same symptoms. Thus, Bell's palsy is a diagnosis of exclusion.
But
before confirming the diagnosis the Doctor may ask the patient to
perform a few facial muscle exercises in front of him like, closing of
eyes, lifting of brow, showing of teeth and frowning, among other
movements.