Intraoperative Neurophysiological Monitoring during Spine Surgery(<SPECIAL ISSUES>Topics of Therapy for Spine Surgery)

Today, intraoperative neurophysiological monitoring (IOM) is standard practice in neurosurgery. Since spine surgery is a functional operation, the importance of IOM is especially high. By offering early detection of reversible neurophysiologic dysfunction during surgery, IOM allows prompt intervention and prevents the occurrence of permanent neurological damage. One of the most important roles of IOM is the promise of improving neurological outcome after surgery. Although IOM is performed in almost all cases of spinal cord tumors generally, it is not necessarily performed when treating degenerative diseases, which are also the most common disease. We are applying IOM to treatments for all of the degenerative diseases. Motor evoked potentials (MEP) and somatosensory evoked potentials (SEP) are used as basic methods and various other monitoring methods such as D-wave or direct stimulation are added according to the individual case requirements. Although direct stimulation of the cerebral cortex is the most stable method to record MEP, transcranial stimulation is generally used in spinal surgery. The transcranial MEP is a simple and useful method ; however, there are some problems that remain to be solved such as the ability to establish an alarm point overcoming the easy effect of muscle relaxants. Moreover, in order to monitor a waveform with a small potential like SEP, it is important to reduce artifacts generated from the operation apparatus. Aquiring such basic methods as MEP or SEP is essential for stable IOM. In this paper, we explain how standard IOM is deployed for spine surgery and multi-channel monitoring for complicated cases.