BAsic information description A paralysis or weakness on one side of the face. The onset may be sudden, or may come on over several days. Bell's palsy involves a cranial nerve and the facial muscles that connect to the nerve. frequent signs and symptoms Sudden paralysis on one side of the face, including muscles connected to the eyelid. Pain behind the ear on the affected side. Flat, expressionless features on one side of the face. Distorted smiles and frowns; drooling. Changes...