The Utility of the Electromyography and Ultrasound Guidance Combination for Botulinum Neurotoxin Injection: Focus on the Added Value of Electromyography.

The efficacy of botulinum neurotoxin (BoNT) is strongly dependent on its accurate delivery to hyperactive muscles and, ideally, to motor endplate regions. Although guidance techniques such as electromyography (EMG) and ultrasound (US) improve injection precision, each technique provides only partial information-either functional or anatomical. Integrating these techniques could enhance targeting accuracy, optimize dose distribution, and reduce off-target effects. A structured PubMed search was performed using terms related to BoNT, spasticity/dystonia, EMG, and US. Filters included clinical trials, randomized controlled trials, meta-analyses and reviews published within the last decade. Fifty-nine studies met the inclusion criteria. The publications were predominantly in neuroscience and rehabilitation journals. Only 17 studies reported combined EMG-US guidance. These focused mainly on stroke and cervical dystonia. While EMG-US integration is a promising strategy, we emphasize the added value of EMG guidance for US approaches, which is particularly important when treating complex neurological conditions involving complex, overlapping muscle activation patterns, or when targeting structures that are inaccessible to conventional imaging techniques. The EMG-US integrated approach is a promising strategy for optimizing BoNT therapy by combining structural visualization with real-time functional assessment. Despite its promising advantages in terms of accuracy and dose optimization, its clinical adoption is limited by a lack of high-quality evidence.