BELL’S PALSY – DESCRIPTION
The seventh cranial or facial nerve passes through a hole in the bony skull just below the ear, to run forward under the parotid salivary gland to supply the muscles of the face.
This nerve can be injured by tumors of the parotid gland or by operations in this area. As this is a motor nerve supplying stimulation to the facial muscles, interference with its function may lead to weakness or paralysis.
The most common cause of facial palsy is inflammation of the nerve.
The swelling causes it to be compressed in the bony canal it passes through to enter the face. Compression leads to loss of function.
In most cases the cause of the inflammation is unknown, although it is thought that some cases may be due to exposure to cold or a draught.
The condition, usually called Bell’s palsy after Sir Thomas Bell, who was professor of surgery in Edinburgh in the 1830s, usually comes on suddenly and may be partial or complete. The person often notices it on awakening.
The paralysed face is flat and without expression, the eyelid cannot be completely closed and food and drink may dribble from the side of the mouth.
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