Comparison of Guided and Unguided Botulinum Injections for Cervical Dystonia: EMG, Ultrasound, and Anatomic Landmarks

Botulinum Toxin type A (BonTA) is the preferred treatment for Cervical Dystonia (CD). However, the success rate is often suboptimal. One of the reasons for treatment failure is the inaccuracy of injections. Some physicians rely on Anatomical Landmarks (AL) for injections, while others use either Ultrasound (US) or Electromyography guidance (EMGg) to improve accuracy.

This retrospective two-center study compared the therapeutic outcomes of AL-based and EMGg injections with USg injections. Demographic and clinical assessments of previous visits and current visits were recorded between 2019 and 2023.

Fifty-one patients were included. Six patients were injected using AL, 14 patients under EMGg, and 31 patients received USg injections. Pain relief was significantly lower for the AL group (40.0% ± 22.4%) compared to both USg and EMGg (81.2% ± 34.0% and 82.2% ± 10.3%, respectively; p = 0.001). Dysphagia was reported in 7.1% of EMGg and 16% of the USg group and none of those treated with AL (p > 0.05).

The results of this study demonstrated that the clinical outcomes of USg and EMGg BonTA injections are comparable and both techniques are superior to AL. The main side effect observed was dysphagia, which was more common in the USg group, although without reaching statistical significance.