ベル麻痺
Bell's palsy is the most common cause of acute facial nerve paralysis. There is no known cause of Bell's palsy, although it has been associated with herpes simplex infection. Bell's palsy may develop over several days, and may last several months, in the majority of cases recovering spontaneously. It is typically diagnosed clinically, in patients with no risk factors for other causes, without vesicles in the ear, and with no other neurological signs. Recovery may be delayed in the elderly, or those with a complete paralysis. Bell's palsy is often treated with corticosteroids.