For an unknown reason, the vast majority of cases affect those between the ages of 19 and 60 and onset is often overnight. It disproportionately affects diabetics, those with upper respiratory ailments like the cold or flu, those who are pregnant, or people who have high blood pressure or are obese.
Bell’s Palsy; Possible Causes
Sir Charles Bell, a 19th-century Scottish surgeon, first described the strange malady that seemingly struck out of nowhere. He wrote about the seventh cranial nerve, the facial nerve, and its influence over different facial muscle groups.
Here’s a little anatomy lesson for you. The 7th cranial nerve originates in the spinal cord. It is the seventh set of nerves, starting from the top, that makes its way between the cervical vertebrae, travels through the skull, beneath the ear and then to muscles on both sides of your face.
This nerve controls facial muscles, lacrimal (tear) glands, salivary glands and a small bone in the middle ear called the stapes, which is responsible for muffling sounds, and transmits taste sensations.
The cause of Bell’s palsy is undetermined, though many scientists believe it can be traced to the same virus that causes cold sores, mononucleosis, chicken pox or shingles -- the herpes simplex virus.