Intraoperative use of transcranial magnetic motor-evoked potentials

Patients undergoing spinal surgery are at risk of sustaining postoperative neurological deficits. Intraoperative multimodal sensory and motor-evoked potentials should decrease this possibility. Transcranial magnetic motor-evoked potentials (tcMMEP) have been used in 13 spinal operations for scoliosis correction with successful recordings obtained in 10 instances. Analysis of waveform amplitude is the most reliable predictor of compromise of corticospinal motor tracts. A narcotic-based anesthetic protocol was used, and muscle relaxant, nitrous oxide, and pCO2 levels were monitored continuously. This method provided a constant degree of central nervous system depression. >