Background and purpose: To review the clinical characteristics and the long-term outcome of patients with hemifacial spasm (HFS) who received botulinum neurotoxin (BoNT) over the past 10 years.
Results: A total of 108 patients received 665 treatments. Mean latency of clinical effect was 5.4 +/- 5.3 days for Botox and 4.9 +/- 4.6 days for Dysport (P > 0.05). Mean duration of clinical improvement was higher after the injection of Dysport than Botox: 105.9 +/- 54.2 and 85.4 +/- 41.6 days respectively (P < 0.01). The percentage of treatment failures was 6.5% for Botox and 4.6% for Dysport (P > 0.05). The doses of Botox significantly increased over time (beta = 0.35, P < 0. 001) whilst Dysport dose remained unchanged (beta = 0.16, n.s.). The duration of clinical benefit slightly increased with Botox (beta = 0.12; P < 0.01), but remained constant for Dysport. Side effects occurred in 17.4% of treatments: 16.7% of patients who had received Botox, and in 19.7% who had received Dysport (P > 0.05). The most common side effects were palpebral ptosis and lacrimation; ptosis and lagophtalmos was more common in Dysport treatments (P < 0.005).
Conclusions: Both brands are effective and safe in treating HFS; efficacy is long-lasting. The differences in outcome and side effects confirm that, albeit the active drug is the same, Botox and Dysport should be considered as two different drugs.