Evidence-based guideline update: Intraoperative spinal monitoring with somatosensory and transcranial electrical motor evoked potentials: Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology and the American Clinical Neurophysiology Society

consolidated the best evidence available on the use of evoked potentials during spinal operations. However, focusing on the value of intraoperative neurophysiological monitoring (IOM) alerts in predicting postoperative motor deficits does not offer new answers to the question "Why use IOM?" The guideline authors agree with the results of a review 2 that supported IOM as a predictive diagnostic tool with a high level of evidence. Prediction alone is insufficient to warrant use of IOM especially when actual outcomes will be revealed almost immediately following the surgery. Also, short-term prediction is insufficient to justify the costs of the specialized equipment, technicians, and professional oversight necessary for proper IOM performance. The evidence for IOM to alter outcomes is weak with only one nonrandomized study 3 showing a 52% rate of preventing neurologic deficits from acting on IOM alerts. In the absence of randomized controlled trials, outcomes research from large observational datasets may clarify the utility of IOM as cost-effectiveness becomes a greater factor in medical decision-making.