Botulinum toxin type A (BTX-A) represent the gold standard therapy for focal dystonia and related hyperkinetic movement disorders. The main advantages of this method are low rate of complications, reversibility and efficacy in reducing spastic hypertonia or abnormal movements. The treatment is safe but it needs to be repeated periodically and some patients do not obtain effective control of the symptoms due to the onset of secondary immune resistance. For this reason we have selected 45 cases already in treatment with botulinum toxin that have been switched to incobotulinumtoxinA. At a median follow up of 8 months the greatest part of the patients, twenty-six (57.7%) remained clinically unchanged; fourteen (31.1%) had a significant clinical improvement and five (11.1%) worsened. We did not observe any general or injection site complications

focal dystonia, botulinum toxin, hemifacial spasm, immune response