Botulinum neurotoxin (BoNT) injections are established as a standard procedure for the treatment of muscles in spastic or dystonic children. Superficial and palpable muscles are easy to inject. In contrast, exact needle placement is more difficult and less controllable in deep muscles or those that are small and difficult to selectively identify. Exact needle placement is, however, essential for optimal functional result, avoidance of side effects and evaluation of therapeutic failures. However, clinical application of BoNT without guidance techniques has been shown to be inaccurate. Several techniques are available to guide needle placement for injection. Electromyography is good, but many muscles may be simultaneously active. Electrical stimulation is uncomfortable and painful and often requires anesthesia. CT guidance necessitates exposure to radiation and is costly. By comparison, the advantages of the ultrasound-guided technique are obvious: real-time observation of the injection readily available easily applicable after a manageable learning period cost effective no serious side effects.

This chapter details the use of ultrasound for injection guidance, and discusses indirect and real-time techniques, and both parallel and perpendicular orientations, for needle placement.