ABSTRACT
ANATOMIC PRINCIPLES FOR BOTULINUM TOXIN INJECTION Successful treatment with botulinum toxin (BoTN) is critically dependent on the appropriate localization of the abnormally activated muscles. The initial and most important step in this process is the physical examination, and as such, a thorough knowledge of muscles, including origin, insertion, and actions, is necessary. This chapter addresses a systematic approach to determine appropriate muscles for BoTN injection, guidance tools to improve therapeutic success, and specifi c sites for injecting the more commonly involved muscles in primary focal dystonia. It is beyond the scope of this chapter to document all the structures that could potentially be injured while injecting with BoTN; care must be taken with every procedure and frequent reference to an anatomy atlas is recommended (1,2).
