A Systematic Review & Meta-Analysis on Criteria for Transcranial Motor Evoked Potential for Intraoperative Neuromonitoring during Spine Surgeries

Abstract

everal Studies of multiple sources show the importance of neuromonitoring during spine surgeries in general, and transcranial motor evoked potential in specific. Discussing it as regards their sensitivity and specificity and detecting its alarm point at which cessation of spine surgery is to be done for assessment of the intraoperative risk, and proceeding with the surgery after evaluation is done. Several factors lead to changes in the uniformity of the reading of the monitoring method, some of which are interpreted as false alarm not causing any damage, others are true, and require immediate intervention to prevent permanent neurological deficit. (21,23) There is no specific alarm point up to this moment. Studies have been conducted to identify the best alarm point for transcranial motor evoked potential, and the outcome was multiple alarm points, each with a certain sensitivity and specificity level. To conclude this, up to this moment, there is not a universally accepted definition for TcMEP alarm criteria, as there is no unified agreement for the qualitative and quantitative changes in the TcMEP recording at which the surgeon must interfere. (18) This review gives Statistical proof that the utilization of a decrease in amplitude of the TcMEP as an alarm point is of value, and that a 50-60% decrease in amplitude of the TcMEP is more sensitive and specific than waiting for a higher decrease in amplitude and hence, better in sensitivity and specificity than waiting for the TcMEP to disappear before raising an alarm for surgery cessation and compromise of patient safety.