Botulinum toxin type A in the treatment of hemifacial spasm: an 11-year experience

In order to evaluate the long-term effect of botulinum toxin type A (BTX) in the treatment of hemifacial spasm (HFS), a retrospective analysis of patients treated at the Movement Disorders Unit of the Division of Neurology, Clinical Hospital, University of São Paulo, School of Medicine from 1993 to 2004 was made. A total of 808 injections with BTX were administered to 54 patients with HFS. The mean duration of improvement per application was 3.46 months and the mean rate of improvement using subjective judgement by the patient was of 83%. Adverse effects, mostly minor, were observed in 64.8% of patients at least once along the period of follow-up and the most frequent of them was orbicularis oris paralysis (38.8%). There was no decrement in response when compared the first and the last injection recorded.