Facial myokymia in the Guillain-Barré syndrome.

Facial myokymia, a unique involuntary movement of facial muscles, is described in a patient with Guillain-Barré syndrome. Although this involuntary movement is most often described with intramedullary lesions of the brain stem, it may also appear with lesions external to the neuraxis. We review the literature and propose a more widespread distribution of potential lesions along the facial nerve pathway, which may produce facial myokymia.