Encyclopedia of Neurological Disorders | Facial Synkinesis

Definition

Facial synkinesis is the involuntary movement of facial muscles that accompanies purposeful movement of some other set of muscles; for example, facial synkinesis may result in the mouth involuntarily closing or grimacing when the eyes are purposefully closed.

Description

Facial synkinesis occurs during recuperation from conditions or injuries that affect the facial nerve, for example during recovery from Bell's palsy. During recovery, as the facial nerve tries to regenerate, some new nerve twigs may accidentally regrow in close proximity to muscles that they wouldn't normally innervate (stimulate). Facial synkinesis may occur transiently, during recovery, or may become a permanent disability.

As with all facial injuries or palsies, facial synkinesis can cause considerable emotional distress. Lack of control...