CPT® Code 64645

Add-On Code

Chemodenervation of one extremity; each additional extremity, 5 or more muscles (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 one 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 of 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 sites of spasm. Proper preparation of the extremity is essential before the injection process, which involves administering the botulinum toxin at carefully chosen sites to ensure effective denervation. For procedures involving five or more muscles in one extremity, the appropriate code is 64644, while 64645 is designated for five or more muscles in each additional extremity.