Microsurgical treatment of hermifacial spasm.

Five cases of idiopathic hemifacial spasm have been successfully treated by operative manipulation of arterial branches compressing the VIIth nerve in the posterior fossa. Terminology, clinical presentation, pathology and therapeutic approaches to hemifacial spasm are discussed. Hearing loss due to operatively induced vascular impairment of the inner ear, a complication in our first case, should be avoidable. Our experience indicates that hemifacial spasm reflects mild chronic compression of the facial nerve. The proposed mechanism is transaxonal excitation between afferent and efferent fibers.