[Motor Evoked Potential and Somatosensory Evoked Potential during Spine and Spinal Surgery].

Spine and spinal cord surgery carries a significant risk of neurological impairment Intraoperative neurological monitoring should now include not only somatosensory evoked potential (SEP), but also motor evoked potential (MEP). While SEP monitors the posterior cord, MEP provides better information regarding the status of the anterior/anterolateral cord. The multimodality SEP and MEP monitoring essentially covers physiological changes of the entire cord, and thereby reduces the risk of development of irreversible neural injury. A 50% drop in SEP amplitude is the universally accepted warning criteria. Conversely, different warning criteria for MEP have been proposed because of MEP especially sensitive to the effects of anesthetic agents. Although evidence lacks that intraoperative evoked potential reduces the rate of neurologic deficits, it is recommended to monitor MEP for spine and spinal surgery, when the spinal cord is considered to be at risk. The anesthesiologist must be familiar with SEP and MEP monitoring to increase the preciseness of the monitoring.