Evaluation of concentrations of botulinum toxin A for the treatment of hemifacial spasm: a randomized double-blind crossover trial

Abstract

ABSTRACT. The aim of our study was to evaluate the efficacy and safety of two concentrations of botulinum toxin A (BTX-A) for the treatment of hemifacial spasm. We randomly divided 20 patients with hemifacial spasm into high-and low-concentration groups; they were administered 50 and 25 U/mL BTX-A injection, respectively. Further, we compared the curative effects and the occurrence of adverse reactions in the two groups. Our results showed that both the concentrations of BTX-A were effective and no significant difference was observed in the onset time and therapeutic efficacy between the two groups; however, the duration of efficacy was longer in the high-concentration group than in the low-concentration group. Patients in both groups had no allergic reactions and systemic toxic reactions, but those in the highconcentration group had more serious adverse reactions and they lasted for longer durations. The adverse reactions in the two groups were not specifically treated, and they resolved in a relatively short time. In conclusion, local injection of BTX-A was effective in treating hemifacial spasm and each concentration of BTX-A had advantages and disadvantages, which indicated that the concentration of BTX-A 1137 ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (1): 1136-1144 (2015) Botulinum toxin A for the treatment of hemifacial spasm can be selected according to the clinical characteristics and willingness of the patients.

Assessing adverse effects of intra-articular botulinum toxin A in healthy Beagle dogs: A placebo-controlled, blinded, randomized trial

“…Injecting BoNT/A in a lower concentration and in a larger volume has been shown to enlarge the area of effect compared to injections of higher concentration and smaller volume [ 92 – 96 ]. In addition, lower concentration has been associated with stronger clinical effect [ 94 ], but no difference in clinical efficacy between low and high concentrations has also been reported [ 93 , 97 ]. Higher concentration has been associated with effect of longer duration but also with more adverse events [ 97 ].…”

“…In addition, lower concentration has been associated with stronger clinical effect [ 94 ], but no difference in clinical efficacy between low and high concentrations has also been reported [ 93 , 97 ]. Higher concentration has been associated with effect of longer duration but also with more adverse events [ 97 ]. We reconstituted the toxin to a concentration of 100IU/ml.…”

Lantox—The Chinese Botulinum Toxin Drug—Complete English Bibliography and Comprehensive Formalised Literature Review

“…Table 2 shows two randomised controlled trials and two interventional studies on LAN for hemifacial spasm, one randomised controlled trial [ 10 ] and one interventional study [ 12 ] by comparing LAN and ONA, and no difference in efficacy and safety was found when converted on a LAN and ONA dose conversion ratio of 1:1. One randomised controlled trial [ 20 ] showed additional posterior auricular muscle injections can reduce acoustic symptoms, and one interventional study [ 21 ] showed that the LAN dose of 50 MU/mL produces longer therapeutic effects and more adverse effects than that of 25 MU/mL whereas the peak efficacies at these two doses are identical.…”

Botulinum Toxin for the Treatment of Hemifacial Spasm: An Update on Clinical Studies

“…The mean duration of the effect was around 12 weeks. There were three RCT studies, of which two were conducted to investigate the efficacy and safety of BoNT in HFS [36,37]. The third study compared pretarsal versus preseptal injections of the orbicularis oculi in 31 patients with HFS reporting that the pretarsal portion of the orbicularis oculi was associated with a significantly high response rate in terms of latency to response, duration of improvement, Jankovic Rating Scale (JRS), self-response scale, and patient satisfaction scale than the preseptal injections [38].…”