[The treatment of hemifacial spasm using botulinum toxin].

Hemifacial spasm is a disagreeable disturbance with involuntary unilateral twitching of the facial muscles. Its most common form is supposedly due to an irritation of the facial nerve at its proximal intracranial segment by vascular structures. Various forms of treatment including surgical procedures are employed, very often without satisfactory results but frequently involving the risk for severe complications. For a few years a new method has been using injection of botulinum toxin into the affected muscles, which in the majority of patients relieves the abnormal movements for about half a year; therefore, this very effective and secure procedure is recommended as first-line treatment of hemifacial spasm.