Adverse reactions of blepharospasm and hemifacial spasm after botulinum toxin A injection and their corresponding responses

Objective To summarize the adverse reactions of blepharospasm (BSP) and hemifacial spasm (HFS) after botulinum toxin A (BoNT-A) injection and offer corresponding responses. Methods Clinical data of 163 BSP patients and 221 HFS patients, admitted to and subjected to BoNT-A injection in our hospital from September 2017 to October 2019, were analyzed retrospectively. Albert and Cohen evaluation scale was used to evaluate the therapeutic efficacy after injection. All adverse reactions were recorded and corresponding responses were proposed. Results The effective rates of BoNT-A injection for BSP and HFS were 97.5% and 100%, respectively. The most common early-onset adverse reactions were local pain (BSP: 13.5%; HFS: 17.2%) and hematoma (BSP: 3.7%; HFS: 4.5%); the late-onset adverse reactions included dry eyes/epiphora (BSP: 9.8%; HFS: 11.3%), incomplete closure of eyelid (BSP: 20.2%; HFS: 20.4%), facial stiffness (HFS: 39.4%) and asymmetry (HFS: 11.8%), and eyelid edema could be noted in a few patients (BSP: 1.2%; HFS: 1.4%). The main measures on reducing or avoiding adverse reactions after injection included appropriate injection apparatus, accurate injection sites, exact drug doses, and consideration of the individual differences of patients. Conclusion BoNT-A is effective in the treatment of BSP and HFS, but it is necessary to avoid early-onset and late-onset adverse reactions to maximize the benefits of patients. Key words: Botulinum toxin type A; Blepharospasm; Hemifacial spasm; Adverse reaction