Accuracy of muscle localization without EMG: implications for treatment of limb dystonia.

Although botulinum toxin is an effective treatment for focal dystonia, the importance of electromyography (EMG) in identifying muscles and guiding injections is unclear. The authors examined the accuracy of muscle localization in 38 muscles in patients with focal hand dystonia without EMG guidance. Only 37% of needle placement attempts reached the target muscles or muscle fascicles. This study demonstrates that EMG guidance is needed for correct localization of desired muscles.