Common causes of intraoperative neuromonitoring failure during thyroid surgery and practical solutions: a narrative review

Chai, Young Jun

doi:2026.6.1.28

J Neuromonit Neurophysiol > Volume 6(1); 2026 > Article

Review Article

Journal of Neuromonitoring & Neurophysiology 2026;6(1):28-37.
DOI: https://doi.org/10.54441/jnn.2026.6.1.28 Published online May 30, 2026.

Common causes of intraoperative neuromonitoring failure during thyroid surgery and practical solutions: a narrative review

Young Jun Chai^1,2

¹Department of Surgery, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul, Republic of Korea
²Transdisciplinary Department of Medicine and Advanced Technology, Seoul National University Hospital, Seoul, Republic of Korea

Correspondence: Young Jun Chai
Email: youngjun_chai@snu.ac.kr

Received: 14 May 2026 • Revised: 16 May 2026 • Accepted: 16 May 2026

Abstract

Intraoperative neuromonitoring (IONM) provides real-time electromyographic assessment of recurrent laryngeal nerve and external branch of the superior laryngeal nerve function during thyroid surgery, supporting nerve identification, functional verification, and surgical decision-making. Technical and pharmacological failures remain clinically important sources of unreliable monitoring. These failures are distinct from true loss of signal caused by neural injury, and their principal sources include endotracheal tube electrode malposition, residual neuromuscular blockade, equipment malfunction, and procedure-specific difficulties encountered in robotic thyroidectomy and transoral endoscopic thyroidectomy vestibular approach. This narrative review categorizes the recognized causes of technical IONM failure, summarizes available evidence for each, and discusses practical preventive and corrective strategies.

Key Words: Intraoperative monitoring, Thyroidectomy, Recurrent laryngeal nerve, Electromyography