Efficacy and safety of abobotulinum injection in patients with focal dystonia

Abstract

Objectives: To investigate the clinical features of focal dystonia and evaluate the efficacy and safety of Abobotulinum injection on these patients. Subjects and methods: A prospective cross-sectional descriptive study on 59 patients and 114 injection sessions of focal dystonia at the Functional Exploration Unit, Hue University of Medicine and Pharmacy Hospital from July 2020 to June 2023. We recorded the dystonia severity by corresponding scale and followed up every one month after the injection to document the maximal subjective improvement and side effects of the injection. Results: The number of patients with hemifacial spasm: blepharospasm: cervical dystonia: limb dystonia: oromandibular dystonia are 17: 12: 20: 8: 2, respectively. Regarding to hemifacial spasm, the primary cause accounted for 82.4%, the average grading scale was 6.1 ± 0.5; the average dose was 80.9 ± 29.9 U Abobotulinum; the proportion of complete and > 50% improvement was 83.9% of injections; the most common adverse effect was facial weakness in 47.0% of patients and 41.9% of injections. In terms of blepharospasm, the mean severity was 5.5 ± 0.9 on the Jankovic’s scale; the average therapeutic dose of 68.1 ± 27.6 helped 90.5% improve > 50% and completely; 1/3 of patients had lagophthalmos, only 2 patient had bruising but no one had ptosis. Cervical dystonia patients had mean Toronto Western Spasmodic Torticollis Rating Scale of 26.3 ± 9.6; using an average dose of 406.1 ± 225.2, which improved 97.8% of injections. The most notable adverse events reported were 1 patient with vasovagal syncope and 1 patient with flu-like symptoms after injection. Limb dystonia data recorded subjective improvement in all patients, and only 1 patient had focal weakness. In 2 cases of closed jaw LTLC, both improved and had no side effects. All of the above side effects were transient and mild. Conclusion: Dystonia involves predominantly the facial and neck muscles, mainly of idiopathic origin. Research has demonstrated its effectiveness in improving symptoms of muscle dystonia, similar to studies conducted worldwide in hemifacial spasm, blepharospasm, and cervical dystonia, with less effectiveness in arm dystonia. Local side effects are quite common in hemifacial spasm and blepharospasm, while they are rare in other forms. Key words: focal dystonia, Abobotulinum, Botulinum toxin injection, cervical dystonia, blepharospasm, hemifacial spasm, oromandibular dystonia, limb dystonia.