Removing the antidromically driven sensory component from cervically evoked motor potentials

The purpose of this paper is to present a model for removing antidromically activated afferent input from cervically elicited neurogenic motor evoked potentials (nMEPs). nMEPs have recently been used clinically, purportedly for monitoring spinal cord motor function, during spine surgery. However, the nMEP response may be due, in part or in whole, to neural signals travelling through sensory rather than motor pathways. This complicates nMEP interpretation and may lead to false conclusions about the status of motor tracts and postoperative motor function. Moreover, transcranial stimulation techniques may also contain similar afferent contamination. Here I suggest a protocol for intraoperative use that should effectively remove such afferent contamination via an afferent action potential collision technique.