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CC BY 4.0 · Arq Neuropsiquiatr 2025; 83(06): s00451809542
DOI: 10.1055/s-0045-1809542
Original Article

EMG versus US: a randomized clinical trial comparing the efficacy in guiding botulinum toxin treatment in cervical dystonia

Mayara Thouin Graciani 
1   Universidade Federal do Rio de Janeiro, Faculdade de Medicina, Departamento de Neurologia, Rio de Janeiro RJ, Brazil.
,
Flávio Henrique de Rezende Costa 
1   Universidade Federal do Rio de Janeiro, Faculdade de Medicina, Departamento de Neurologia, Rio de Janeiro RJ, Brazil.
2   Universidade Federal do Rio de Janeiro, Faculdade de Medicina, Departamento de Medicina Interna, Rio de Janeiro RJ, Brazil.
,
Ana Lucia Zuma de Rosso 
1   Universidade Federal do Rio de Janeiro, Faculdade de Medicina, Departamento de Neurologia, Rio de Janeiro RJ, Brazil.
,
Gil Fernando Salles 
2   Universidade Federal do Rio de Janeiro, Faculdade de Medicina, Departamento de Medicina Interna, Rio de Janeiro RJ, Brazil.
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Abstract

Background

Botulinum toxin type A (BoNT-A) is considered the first-line therapy for cervical dystonia.

Objective

To compare, in a randomized trial, the efficacy of treatment with BoNT-A guided by ultrasound (US) and electromyography (EMG) in patients with idiopathic cervical dystonia.

Methods

A total of 40 patients (20 in each group; mean age: 54 years; 45% of female subjects; mean disease duration: 10.7 years) were randomized to either US- or EMG-guided BoNT-A treatment. The efficacy of BoNT-A was assessed through changes in the scores on the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) before and 4 to 6 weeks after the treatment. The differences in the absolute and relative changes in the total TWSTRS scores and in its components (severity, incapacity, and pain) between the groups were evaluated.

Results

The US and EMG groups were well balanced in relation to baseline and demographic characteristics. After the BoNT-A treatment, there was a mean reduction in the TWSTRS score of 8 points (relative reduction of 23%) equally between the US and EMG groups (mean difference in absolute decrease of 0.1 point; p = 0.97; and mean difference in relative decrease of 2%; p = 0.89). There were no differences in the declines in the scores on the TWSTRS components, nor when the improvements in the TWSTRS scores were dichotomized as more significant or lower reductions (all p-values > 0.3).

Conclusion

The present randomized trial did not demonstrate any difference in improvements between BoNT-A treatment guided by US or EMG in patients with idiopathic cervical dystonia.

Clinical Trial Registration

ReBEC Identifier: RBR-33dd4p4.

Keywords

Botulinum Toxins - Torticollis - Electromyography - Ultrasonography

Authors' Contributions

Conceptualization: MTG, FHRC, ALZR; Data curation: MTG, FHRC, GFS, ALZR; Formal analysis: FHRC, GFS; Funding acquisition: ALZR; Investigation: MTG, FHRC; Methodology: MTG, FHRC; Project administration: MTG, FHRC, GFS, ALZR; Resources: ALZR; Software: GFS; Supervision: FHRC, GFS; Validation: MTG, FHRC, GFS; Visualization: MTG, FHRC, GFS; Writing – original draft: MTG; Writing – review & editing: MTG, GFS.


Data Availability Statement

The contents underlying the research text are included in the manuscript.


Editor-in-Chief: Hélio A. G. Teive 0000-0003-2305-1073.


Associate Editor: Vitor Tumas 0000-0003-2402-2709.




Publication History

Received: 23 September 2024

Accepted: 17 April 2025

Article published online:
20 June 2025

© 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution 4.0 International License, permitting copying and reproduction so long as the original work is given appropriate credit (https://creativecommons.org/licenses/by/4.0/)

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Bibliographical Record
Mayara Thouin Graciani, Flávio Henrique de Rezende Costa, Ana Lucia Zuma de Rosso, Gil Fernando Salles. EMG versus US: a randomized clinical trial comparing the efficacy in guiding botulinum toxin treatment in cervical dystonia. Arq Neuropsiquiatr 2025; 83: s00451809542.
DOI: 10.1055/s-0045-1809542