Electrophysiological study on the pathology of synkinesis after facial nerve paralysis.

By conducting electrophysiological tests on patients with facial nerve paralysis, the characteristics of synkinesis and the mechanisms of its manifestations were examined. The subjects were 114 patients of facial nerve paralysis on whom electroneurography (ENoG) and the blink reflex were conducted. As a result, it was indicated that synkinesis could be determined by the blink reflex, and that the frequency of synkinesis manifestation increased with severity of paralysis. From examination during the latent period, early component (SI) recognized in the cases of synkinesis was found to be the waveform which passed the fibers with a slow conducting speed. It was not related to the degree of degeneration of nerves for either the severe or light degeneration of nerves. From the above result it was concluded that synkinesis is generated as a misdirection of reproduced nerves.