Botulinum toxin injection for spasmodic torticollis: increased magnitude of benefit with electromyographic assistance

To determine the usefulness of EMG-assisted botulinum toxin (BOTOX) injections for the treatment of spasmodic torticollis (ST), we randomized 52 ST patients into two groups and studied them prospectively. In one group [(E+C)RX, N = 28], the muscles were selected for BOTOX injection using both clinical and EMG examination and then injected with EMG assistance. In the second group [(C)RX, N = 24] the muscles were selected for BOTOX injection based solely on clinical examination and injected without EMG assistance. The percentage of patients showing any improvement after BOTOX as similar in both the (E+C)RX and (C)RX groups. A significantly greater magnitude of improvement was present in the (E+C)RX group, as well as a significantly greater number of patients with marked improvement. In particular, patients with retrocollis, head tilt, and shoulder elevation demonstrated additional benefit with EMG-assisted BOTOX injection. EMG assistance may be effective because the technique increases the ability to effectively identify and treat the deep cervical muscles.