A syndrome characterized by the acute onset of unilateral facial paralysis which progresses over a 2-5 day period. Weakness of the orbicularis oculi muscle and resulting incomplete eye closure may be associated with corneal injury. Pain behind the ear often precedes the onset of paralysis. This condition may be associated with Herpesvirus 1, Human infection of the facial nerve. (Adams et al., Principles of Neurology, 6th ed, p1376)