Progress in Intraoperative Neurophysiological Monitoring for the Surgical Treatment of Thoracic Spinal Stenosis

Abstract

Thoracic spinal stenosis (TSS) is a group of clinical syndromes caused by thoracic spinal cord compression, which always results in severe clinical complications. The incidence of TSS is relatively low compared with lumbar spinal stenosis, while the incidence of spinal cord injury during thoracic decompression is relatively high. The reported incidence of neurological deficits after thoracic decompression reached 13.9%. Intraoperative neurophysiological monitoring (IONM) can timely provide information regarding the function status of the spinal cord, and help surgeons with appropriate performance during operation. This article illustrates the theoretical basis of applying IONM in thoracic decompression surgery, and elaborates on the relationship between signal changes in IONM and postoperative neurological function recovery of the spinal cord. It also introduces updated information in multimodality IONM, the factors influencing evoked potentials, and remedial measures to improve the prognosis. should be alert to the existence of false-negative tests during thoracic decompression surgery, and endeavor to achieve timely detection and appropriate treatment. Deteriorated signals and the achievement of the "alarm point" during the operationThe present criterion for an abnormal SEP, namely a 50% decrease in amplitude and/or a 10% increase in latency, has been widely used in the surgical treatment of TSS. 14,16 In the study by Taher Multimodality intraoperative monitoring (MIOM)SEP is a method of monitoring the sensory pathway, and it cannot directly monitor the motor conduction pathway in the anterior column of the spinal cord. This is the basic cause of false-negative SEP monitoring. Factors influencing evoked potentialsThe intraoperative signal changes are mainly caused by factors related to anesthesia, physiology and surgery. If no significant signal recovery after these treatments, Stagnara wake-up test and shock therapy using methylprednisolone are suggested. Shock therapy involves an initial bolus of 30 mg/kg of methylprednisolone followed by an infusion of 5.4 mg/kg/h for 23 hours. 35 Methylprednisolone therapy should be maintained till the end of the surgery.After the surgery, whether to apply the drug continuously or to change to other rehabilitation treatments depends on the recovery status from the postoperative neurological functional evaluation. Summary and prospectsIn summary, the application of IONM during thoracic