The importance of electromyographic guidance and electrical stimulation for injection of botulinum toxin.

The importance of EMG or electrical stimulation for guiding injections of botulinum toxin in limb muscles to treat dystonia or spasticity is based more on theoretical and preclinical data than on controlled clinical trials. Questions remain about the preferred administration of botulinum toxin for these conditions. Future clinical research is necessary to show clearly functional benefit of any particular injection localization method.