Modern approach to the resection of carotid region schwannoma: The utility of continuous intraoperative neurophysiological monitoring

Objective: In the extracranial carotidopaty the most frequent paragangliomas are chemodectomas; because of the complex anatomy of the surrounding structures, a lateral neck mass may arise by muscular, osseous, epithelial, mesenchymal or nervous tissues: a rare presentation is the vagus nerve neoplasia. The described technique compares the intraoperative neurological monitoring methods and their usefulness in avoiding neurological damage. Methods: The surgical procedure was totally performed under neurophysiological monitoring with: A) Electroencephalogram. B) Transcranial electric motor evoked potential (MEP) with recording of left and right laryngeal and cricothyroid muscles. C) Somatosensory evoked potential (SEP) by the stimulation of the right and left median nerves. D) Free run registration from laryngeal and cricothyroid bilateral muscles. During the procedure was performed the direct stimulation (DNS) of the right vagus nerve and registration from the target muscles. Results: The DNS of the neck mass was associated with finding of eloquent and non–eloquent nervous tissue allowing a safe gross total resection. The SEP and MEP did not show any significative changes during the surgical treatment. Conclusions: Multidisciplinary approach is mandatory to perform perioperative evaluation and safe surgical treatment, which is the gold standard of Schwannoma treatment.