CPT® Code 64643

Add-On Code

Chemodenervation of one extremity; each additional extremity, 1-4 muscle(s) (List separately in addition to code for primary procedure)

Chemodenervation is a medical procedure aimed at alleviating involuntary muscle contractions or spasms that can occur in various conditions such as dystonia, cerebral palsy, or multiple sclerosis. This technique involves the injection of botulinum toxin, either type A or B, directly into the targeted muscles of an extremity. The primary mechanism of action is the temporary paralysis of the muscle, achieved by blocking the release of acetylcholine at the peripheral nerve endings. This interruption in neuromuscular transmission effectively reduces the muscle's ability to contract, thereby providing relief from the symptoms associated with these conditions. The selection of specific muscles for injection is typically guided by electromyography or through a physical examination of the affected extremity, where the physician palpates the muscles and identifies the precise locations of muscle spasms. Prior to the injection, the extremity is prepared to ensure a sterile environment. The procedure is designed to target the affected muscle or muscle group at carefully chosen sites to achieve optimal denervation. For coding purposes, CPT® Code 64642 is utilized for the chemodenervation of 1-4 muscles in one extremity, while CPT® Code 64643 is designated for the chemodenervation of 1-4 muscles in each additional extremity.