CPT® Code 64617

Chemodenervation of muscle(s); larynx, unilateral, percutaneous (eg, for spasmodic dysphonia), includes guidance by needle electromyography, when performed

Chemodenervation is a medical procedure aimed at alleviating involuntary muscle contractions or spasms that occur in the vocal cord muscles of the larynx. These spasms are often associated with a neurological condition known as spasmodic dysphonia, which can also be referred to as laryngeal dystonia or spastic dysphonia. This condition significantly impacts the quality of speech, making it difficult for individuals to communicate effectively. The procedure involves the injection of botulinum toxin, either type A or B, directly into the affected muscle. This toxin works by inducing temporary muscle paralysis through the inhibition of acetylcholine release at the peripheral nerve endings, thereby disrupting the neuromuscular transmission of nerve impulses. The specific muscle sites for injection are determined using electromyography (EMG), a technique that allows for precise localization of the muscles involved. During the procedure, a hollow EMG needle, which is connected to an EMG recorder, is utilized to administer the injection. The patient may be positioned either supine or seated with their head extended to facilitate access to the larynx. The thyroid and cricoid cartilages are palpated to locate the midline of the cricothyroid membrane. Depending on the type of spasmodic dysphonia, the needle is inserted percutaneously into the appropriate muscle: the thyroarytenoid muscle for abductor spasmodic dysphonia or the posterior cricoarytenoid muscle for adductor spasmodic dysphonia. Typically, the injection is performed unilaterally during the initial visit, with the opposite side being treated in a follow-up appointment scheduled approximately two weeks later. The CPT® code 64617 specifically denotes this unilateral procedure.