A patient suffering from idiopathic dystonia is seen today and receives the following Botulinum injections:...

For the injections, CPT® code 64642 is used for chemodenervation of one extremity; 64643 for each additional extremity, and 64647 for chemodenervation of muscles in the paraspinal region. The modifier -50 is added to 64642 and 64643 to indicate bilateral procedures. According to CPT® guidelines, when multiple sites are treated, each site is coded separately, and appropriate modifiers are used.

AMA ' s CPT® Professional Edition (current year), Surgery section, Nervous System.