Sonographic Guide for Botulinum Toxin Injections of the Neck Muscles in Cervical Dystonia.

Intramuscular botulinum toxin (BoTX) injection is the first-line treatment of cervical dystonia. Poor treatment outcomes and some side effects, however, have been reported after BoTX applications. One of the most important reasons is incorrect localization of the needle during toxin injections. Without imaging, it is impossible to verify precise needle positioning in the proper muscle. Ultrasound has been recommended because of its high capability in illustrating most of the neck muscles. This review article discusses how ultrasound imaging can be used to scan/access neck muscles, mainly from the perspective of BoTX injections.