motor evoked potentials
Also written as: MEPs — Motor Evoked Potentials
Electrophysiological signals used during surgery to monitor motor pathway integrity by stimulating the motor cortex and recording muscle responses.
Full Definition
Motor evoked potentials (MEPs) are neurophysiological signals obtained by electrically or magnetically stimulating the motor cortex and recording the resulting electrical activity in peripheral muscles. During neurosurgery, MEPs are used as part of intraoperative neurophysiological monitoring to assess the functional integrity of the corticospinal tracts in real-time. The technique involves placing stimulating electrodes over the motor cortex and recording electrodes in muscles innervated by the corticospinal tract. Changes in MEP amplitude, latency, or morphology can indicate impending or actual injury to motor pathways, allowing surgeons to modify their technique to prevent permanent motor deficits. MEP monitoring is particularly valuable during spinal cord surgery, brain tumor resection near motor areas, and brainstem procedures.
Usage
Usage note: Commonly abbreviated as MEPs. Document baseline values and any significant changes during monitoring.
In Context
- "MEPs remained stable throughout the spinal cord tumor resection, indicating preserved motor function." — Intraoperative monitoring report
- "Loss of motor evoked potentials prompted immediate irrigation and position adjustment." — Intraoperative complication note