The symposium from which this book originates represents a sig nificant watershed in the field of intraoperative neural monitoring, since the participants concluded that electrophysiologic monitoring techniques should be considered a "standard of care" for surgical pro cedures that place the central nervous system (CNS) at risk for injury. Specifically, it was agreed that the somatosensory-evoked potential (SEP) is a remarkably reliable and sensitive indicator of several aspects of CNS function, and should be routinely employed as an intraopera tive monitor during many neurosurgical and orthopedic procedures. The significance of this conclusion cannot be overstated, for at the time of this writing, intraoperative monitoring methods based on evoked-potential analyses are still considered experimental and are not in routine use. The reasons for this are not clear, given the accu mulation of literature and expertise on this subject over the past five years. Granted, the cost of electrophysiological monitoring equip ment is high, but only initially. The benefits of injury prevention far outweigh these costs, from both medical and economic viewpoints. It is our sincere hope and goal that the medical community be made aware of the value of intraoperative neural monitoring.