[Bell's palsy: a broad differential diagnosis].

Peripheral facial palsy is a common clinical symptom and is most often caused by Bell's palsy. The pathogenesis is largely unknown, but inflammation of the facial nerve, possibly after a viral infection, may play a role. Bell's palsy has a monophasic course with usually - but not always - a good recovery. Even though Bell's palsy exhibits clear clinical features, in clinical practice diagnosis and choice of treatment remain difficult and other causes of an isolated facial palsy may easily be overlooked.