Though Bell's palsy is a common disorder that may occur in persons of any age from infancy to old age, little or no progress was reported in its treatment until recently. This familiar seventh nerve paralysis is usually of acute onset. The lesion has been described as inflammation of the nerve or of its sheath within the facial canal or elsewhere. Edema of the seventh nerve, of its sheath, or of the periosteal tissues of the surrounding facial canal, from noninflammatory changes, has also been thought capable of producing sufficient compression to disrupt function.
There is much controversy over the etiology of Bell's palsy, though several plausible theories have been advanced. Park and Watkins have listed several of the causes that have been suggested as follows: (1) specific infectious neuritis, (2) vascular dysfunction with secondary ischemia of the facial nerve, (3) refrigeration, (4) subclinical mastoid infection involving the region of
Robison WP, Moss BF. TREATMENT OF BELL'S PALSY WITH CORTISONE. JAMA. 1954;154(2):142-143. doi:10.1001/jama.1954.02940360040011