Electrophysiologic Study of Perioperative Monitoring of the Recurrent Laryngeal Nerve: Impaired Vocal Cord Movement After Thyroidectomy

Paralysis of the recurrent (or inferior) laryngeal nerve (RLN or ILN) is one of the most common and most serious complications of thyroid surgery. Neuromonitoring of the inferior laryngeal nerve (ILN or recurrent) is a technique currently used during thyroidectomy to locate ILN during dissection. Detector electrodes are placed in contact with vocal muscle which is stimulated electrically at the location of ILN, producing an acoustic and visual signal. This is a basic electromyographic technique whose diagnostic and prognostic potential for the entire neuromuscular system has not yet been fully explored. The study of action potentials generated by the stimulation-detection of nerves ILN and vagal nerves at the beginning and end of dissection, notably the decrease in amplitude, could allow a diagnosis during the course of surgery making it possible to diagnose lesions of the nerve and guide the surgeon in his surgical decisions, thus avoiding the risk of bilateral recurrent paralysis. It could also enable the surgeon to give a prognosis for functional recovery.