[The autoparalytic syndrome--a leading symptom of postparetic facial function].

Contradictory clinical and electromyographical findings following operations on the facial nerve have given rise to an analysis of the functional anatomy of the mimic musculature. This has led to the isolation of two sphincter systems in one half of the face to which all muscles on that side belong and which are innervated independently. Because of post-operative fiber aberrations, the innervational autonomy of both systems is lost, thus leading to mass movements. Since each system contains a number of antagonists, a mutual blocking that is the result of the heteromorphous neurotization occurs, producing the symptoms of a residual paresis, although these "weak" muscles are well reinnervated. These anatomical-functional relationships also offer an explanation for the fact that a clinically visible functional rehabilitation of the frontalis muscle rarely occurs following a neuroplasty in the truncal region of the facial nerve. The term "autoparalytic syndrome" thus offers itself as a description of this pathomechanism.