Abnormal facial movements. Guide to differential diagnosis.

Spontaneous facial movements are disturbing to those who have them, yet some such movements are benign and cause no more than cosmetic embarrassment. Other abnormal facial movements, however, are more serious and can be associated with neurologic disorders such as multiple sclerosis, brainstem tumor, peripheral neuropathy, and Guillain-Barré syndrome. Occasionally, an abnormal movement of the face is the first sign of such an underlying disorder. Accurate differential diagnosis of these perplexing movement disorders is imperative in determining prognosis.