Incomplete Paralysis With Synkinesis

In many cases, acute facial nerve paralysis is followed by a variable degree of recovery. When the nerve injury is incomplete, functional recovery is usually complete, with no long term consequences. When the nerve injury is considerable, recovery may be incomplete. Regenerating nerve fibers may be “confused” and may not follow their correct paths back to their correct muscles. The nerve that originally delivered signals to the muscles surrounding the mouth may inadvertently start delivering signals to the muscles surrounding the eye and vice versa. Attempts to close the eye then become associated with lip movements and attempts to close the lips or to smile become associated with eye closing or brow movement. In other circumstances the face may become “frozen” in position. In these cases, a single expression is continually and constantly expressed.