Efficacy and side effects of botulinum toxin treatment for blepharospasm and hemifacial spasm

PURPOSE: To analyse the effectiveness and rate of side effects of botulinum toxin treatment for blepharospasm and hemifacial spasm. METHODS: In a prospective trial, 81 patients with blepharospasm and 70 with hemifacial spasm were treated with botulinum toxin A in the neuroophthalmology clinic at St Vincent's Hospital, Melbourne. Some 989 treatments were given and the mean follow-up time was 28.7 months. RESULTS: The duration of action was longer for patients with hemifacial spasm than for those with blepharospasm (median 12.0 weeks compared with 7.0 weeks, P < 0.0001). There was no change in the duration of effect over time with repeated treatments of the same dose (F = 0.4, P > 0.05). Once an effective dosage was reached, increasing the dose further did not prolong the duration of effect. There were no systemic side effects, but there were a number of local transient side effects. The most significant side effect was ptosis, which occurred in 12% of treatments given to those patients with blepharospasm and hemifacial spasm. CONCLUSION: Botulinum toxin is an effective treatment for blepharospasm and hemifacial spasm, but there are a number of side effects, the most significant being ptosis.