Subtotal Evulsion of the Facial Nerve in Hemifacial Spasm

Abstract

The various surgical procedures performed for hemifacial spasm whereby part of the facial nerve is sectioned, indicate: (1) An intermingled intrafacial arrangement of the various nerve filaments. This arrangement differs from the classical concept that there is a specific regional representation of the peripheral branches and of their tracts in the main trunk. The intermingling of all peripheral filaments in the main trunk explains why even a small portion of the main trunk may represent functionally most of the face. (2) The presence of a wide peripheral anastomosing network connecting the peripheral branches in such a manner that one branch may functionally represent the other branches if they are severed.

On the basis of these anatomical observations and because of the frequent recurrence of facial spasm after most prescribed surgical procedures, evulsion of most peripheral twigs is recommended in certain cases. The mandibular branch and one or two superior branches are left. This is considered a compromise surgical procedure, resulting in only slight facial weakness as well as possible recurrence of mild and relatively sparse spasmodic movements.

Further theoretical conclusions from the intrafacial fascile arrangements constitute an a priori limitation of surgical results from facial nerve anastomosis and grafting in traumatic cases.