Objective: Cervical Dystonia (CD) is the most common form of focal dystonia involving the muscles of the neck and sometimes the shoulders. ¹ There are several categories of drugs (anticholinergic, antidopaminergic, dopaminergic, gabaergic) reported being effective in CD patients on the basis of uncontrolled studies². Today we use Botulinum toxin type A as the first-line therapy for CD. However, there is no definitive medical treatment for cervical dystonia so far ^3-6 The most common side effects of botulinum toxin injection in cervical dystonia treatment include dysphagia, ptosis, cervical muscle weakness, dry mouth^2,  and atrophy. ⁸  There is not enough study that evaluated muscle atrophy after Botulinum toxin injection, and studies that measure muscle atrophy quantitatively, and describe risk factors related to this atrophy. In this study, we measured the amount of atrophy by MRI, and evaluate risk factors related to this atrophy.

Background: There is a study by Durand and his colleagues about muscle atrophy caused by botulinum toxin injection for cosmetic purposes, in which there is not sufficient data about the degree of atrophy, classification of atrophy, and precise mechanism of atrophy ⁹.

Method: All subjects were recruited from 2018 to 2020 in the Movement Disorders clinic of Shohada-e-Tajrish university hospital.
The study was approved by the local ethics committee in Shahid Beheshti University of Medical science (IR.SBMU.RETECH.REC.1399.258), and written informed consent was obtained from all subjects.
A soft-tissue cervical MRI was performed before treatment. Patients underwent treatment with abobotulinumtoxinA every 3 months, and after 12 months we performed a second cervical soft tissue MRI.

Results: In the study, twenty-five patients were recruited. All 25 patients did the first MRI, but the second MRI was performed for seven patients.
The study was conducted on two men (28.6%) and five women (71.4%).
Mean age of participants was 40 ± 12.76 years  and five were females ( 71.4%)
This study showed that the number of injections and amount of botulinum toxin injections are related to the amount of atrophy.

Conclusion: Repeated botulinum toxin injection causes a decrease in muscle volume and increases in the degree of atrophy with increasing injection times and doses in older patients. There has been no correlation between atrophy and gender, muscle type, or BMI, which can result from having few patients in the study.

References: 1. Quick facts about cervical dystonia (spasmodic torticollis): a consensus update. Mov Disord. Dystonia Medical Research Foundation. https://dystonia-foundation.org/what-is-dystonia/types-dystonia/cervical-dystonia/. Published 2013. Accessed.
2. Costa J, Espírito-Santo C, Borges A, et al. Botulinum toxin type A therapy for cervical dystonia. Cochrane Database Syst Rev. 2005(1):Cd003633.
3. Contarino MF, Van Den Dool J, Balash Y, et al. Clinical Practice: Evidence-Based Recommendations for the Treatment of Cervical Dystonia with Botulinum Toxin. Front Neurol. 2017;8:35.
4. Castelão M, Marques RE, Duarte GS, et al. Botulinum toxin type A therapy for cervical dystonia. Cochrane Database Syst Rev. 2017;12(12):Cd003633.
5. Marsili L, Bologna M, Jankovic J, Colosimo C. Long-term efficacy and safety of botulinum toxin treatment for cervical dystonia: a critical reappraisal. Expert Opin Drug Saf. 2021;20(6):695-705.
6. Comella CL, Jankovic J, Truong DD, Hanschmann A, Grafe S. Efficacy and safety of incobotulinumtoxinA (NT 201, XEOMIN®, botulinum neurotoxin type A, without accessory proteins) in patients with cervical dystonia. J Neurol Sci. 2011;308(1-2):103-109.
7. Salari M, Sharma S, Jog MS. Botulinum Toxin Induced Atrophy: An Uncharted Territory. Toxins (Basel). 2018;10(8).
8. Durand PD, Couto RA, Isakov R, et al. Botulinum Toxin and Muscle Atrophy: A Wanted or Unwanted Effect. Aesthet Surg J. 2016;36(4):482-487.

« Back to 2022 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/evaluation-of-atrophy-after-botulinum-toxin-injection-for-cervical-dystonia-by-mri/