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
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
