Long term results of botulinum toxin type A (Dysport) in the treatment of hemifacial spasm: a report of 175 cases

摘要

OBJECTIVE— To describe the long term efficacy andside effects of the treatment of hemifacial spasm with Dysport and toevaluate two different sites of injection to hopefully reduce side effects.
METHODS—This study was designed as a prospectivedescriptive study. Injections were made subcutaneously around the eye.Peak improvement was subjectively assessed by using a visual analoguescale and reported in percentages (0-100%). Duration of improvementwas assessed subjectively and reported in months.
RESULTS—Of 175 cases, 17 were lost to follow upand were excluded. 855 treatments were injected in the remaining 158 patients with a median of 4 treatments. The response rate was 97%. Of855 treatments, the adjusted mean peak and duration of improvement was77.2 (95% confidence interval (95%CI) 74.7-79.4)% and 3.4 (95%CI3.2-3.6) months respectively. In 158 patients (complete group), thelong term results from the first to the 12th treatment showed that themean peak improvement ranged from 72.70 to 80.10% and the duration ofimprovement was 2.60 to 3.71 months. It remained constant throughout(p=0.40, p=0.87 respectively). The most common side effect was ptosis.Of the 158 patients, 21 completed 12 treatments (subgroup). A separateanalysis of this group disclosed a mean peak and duration ofimprovement from the first to 12th treatments ranging from 70.00 to78.10% and 2.65 to 4.31 months respectively. Analysis of variance withrepeated measures showed no significant variation of peak and durationof improvement over the first to the 12th treatments (p=0.38, p=0.38respectively). Only 3% of the treatments were unsuccessful butresponded to subsequent treatments. The incidence of ptosis was reducedfrom 27.17% to 9.68% by moving the injection site to the lateral partof orbital orbicularis oculi without any loss of efficacy. The yearlycost of Dysport is considerably less than Botox.
CONCLUSION—This study is the first to show, indetail, the long term results of treatments of hemifacial spasm withDysport. The efficacy is constant throughout the first to 12thtreatments in both the complete group andsubgroup. Ptosis can be reduced by moving the injection site further upto the lateral part of the orbital orbicularis oculi. The efficacy ofDysport is comparable with Botox® in long term follow up.