Outcomes of a regional variant of botulinum toxin type A in the treatment of essential blepharospasm and hemifacial spasms: A retrospective study

PURPOSE: The aim of this study was to report the outcomes of a regional variant of botulinum toxin type A (BtA) in essential blepharospasm and hemifacial spasm. METHODS: The medical records of all patients with facial dystonias, who received at least one dose of BtA between May 2016 and April 2017 were retrospectively evaluated. The pre- and post-injection severity of symptoms, graded using the Jankovic rating system for essential blepharospasm and the Samsung Medical Center grading system for hemifacial spasm, the complications after each sitting, and the mean symptom-free interval were recorded. A correlation analysis was done to identify factors associated with longer symptom-free intervals. A P value < 0.05 was considered statistically significant. RESULTS: The mean age at presentation was 56.62 ± 10.56 years. The mean duration of follow-up was 1.86 ± 2.06 years. The modal disease severity reduced from 5 to 0 in essential blepharospasm and from 2 to 0 in hemifacial spasm a week after injection of botulinum toxin. The mean symptom-free intervals with doses of 20, 22.5, 25, 30, and 50 units were 102.1 ± 44.7, 132.4 ± 35.3, 147.2 ± 61.6, 124.4 ± 55.1, and 142.4 ± 59.7 days, respectively. The commonest complication was lagophthalmos (26.3%; n = 20). Injections for primary dystonias were associated with longer disease-free intervals than those for secondary dystonias (P = 0.02). In nine sittings, the dose was increased for increased severity or presumed resistance, which resulted in a significant increase in the symptom-free interval (P = 0.004) without an increased incidence of complications (P = 0.48). CONCLUSION: BtA is safe and effective in the treatment of facial dystonias. The drug is more efficacious for primary facial dystonias.