Near-complete tongue transection during spinal surgery with transcranial MEP monitoring: A case report.

RATIONALE: IONM, especially transcranial MEPs, is a cornerstone in preventing neural injury during spinal surgery. However, transcranial stimulation may result in forceful jaw closure, causing oral trauma such as tongue lacerations, dental injury, or rarely, airway compromise. This case underscores the importance of recognizing and preventing rare but serious complications related to intraoperative neuromonitoring. PATIENT CONCERNS: A 55-year-old female with progressive lower limb weakness and thoracic kyphotic deformity underwent multi-level posterior spinal fusion and vertebral column resection. DIAGNOSES: A near-complete laceration of the left lateral tongue was noted during emergence from anesthesia, suggesting bite-induced injury from MEP monitoring. INTERVENTIONS: The patient underwent immediate otolaryngology consultation and primary repair under general anesthesia. Postoperative management included conservative treatment with topical policresulen and monitoring. OUTCOMES: The lesion healed fully without infection or further intervention. The patient was discharged in stable condition. LESSONS: This report highlights a severe yet preventable complication of MEP monitoring. Soft bite block use, careful oral positioning, and intraoperative vigilance - especially in prolonged prone procedures - are essential preventive strategies. Early recognition and timely intervention are crucial for minimizing morbidity.