Efficacy of intraoperative monitoring of transcranial electrical stimulation–induced motor evoked potentials and spontaneous electromyography activity to identify acute-versus delayed-onset C-5 nerve root palsy during cervical spine surgery

Abstract

The risk of new-onset deltoid muscle weakness following cervical spine surgery is greatest for patients undergoing 2-level corpectomies involving C-4 and C-5. Transcranial electrical stimulation-induced MEP monitoring is a highly sensitive and specific technique for detecting C-5 radiculopathy that manifests immediately upon waking from anesthesia. While the absence of sustained spEMG activity does not rule out nerve root irritation, the presence of excessive neurotonic discharges serves both to alert the surgeon of such potentially injurious events and to prompt neuromonitoring personnel about the need for additional tceMEP testing. Delayed-onset C-5 nerve root injury cannot be predicted by intraoperative neuromonitoring via either modality.