Hemifacial spasm due to peripheral injury of facial nerve: a nuclear syndrome?

Four cases of hemifacial spasm (HFS) are reported. The spasm followed a few months after injury to a peripheral branch of the seventh nerve. An EMG examination of facial muscles disclosed the typical finding of HFS: spontaneous activity, paradoxical cocontraction, and diffusion of spontaneous or provoked blinking. A nuclear involvement, secondary to the nerve lesion, is the most likely pathophysiological explanation for similar cases in HFS.