What forms the basis for artifact rejection in neurophysiologic monitoring?

The basis for artifact rejection in neurophysiologic monitoring relies on the assumption that responses of excessive amplitude are likely indicative of artifact. In this context, an artifact refers to unwanted signals that can obscure or distort the true physiological signals being recorded. These can arise from a variety of sources, such as muscle contractions, electrical interference, or equipment malfunction.

When monitoring brain or spinal cord activity during surgeries, clinicians look for signals that deviate significantly from expected physiological values. If a signal shows excessive amplitude, it stands out as likely being unnatural or false—hence, it is regarded as a potential artifact. The monitoring system can then apply algorithms or filtering techniques to minimize the impact of these artifacts, preserving the integrity of the true physiological signals.