IONM of the Recurrent Laryngeal Nerve

Thyroid surgery can pose risk to both the right and the left recurrent laryngeal nerves (RLN) in a single surgical procedure. Unilateral vocal cord palsy (VCP) can lead to morbidity related to changes in voice, especially in professional voice users, as well as potential dysphagia and aspiration, while bilateral VCP may require tracheostomy. Visualization of the RLN during surgery has been considered the gold standard for preventing injury to the RLN; however, an intraoperatively visualized and structurally intact nerve does not necessarily represent a postoperatively functioning nerve. Neural monitoring has increasingly gained the attention of surgeons performing thyroid and parathyroid surgeries around the world. Current studies suggest that a majority of general and head and neck surgeons use neural monitoring in at least some of their thyroid surgical cases. This chapter presents a historical overview and usage patterns of intraoperative neural monitoring (IONM) of the RLN and discusses its impact on surgical practice, including intraoperative applications of IONM, medicolegal aspects and standards of IONM, normative data, as well as current advances in IONM such as continuous IONM.