Table 1.

Definitions of statistically significant alerts

True-positive alert	Significant alert in NMEP/SSEP signals indicative of an ‘evolving’ injury that (1) was irreversible despite all interventional measures and was followed by a postoperative neurologic deficit or (2) responded favorably to intervention (improved to within 25% of the initial stable baseline value)
False-positive alert	Significant alert that could not be reversed to within 25% of the stable value, but the patient awoke without any postoperative sensory and/or motor deficit
True-negative alert	No critical changes and the patient awoke neurologically intact
False-negative alert	Patient awoke with a new neurologic deficit with (1) No significant change in NMEP/SSEP (2) a relevant signal change had resolved to within 25% of baseline following intervention