O2-E-48. Control of Br (E)-MsEP used in the intraoperative spinal cord monitoring during the surgery of cervical spine

Abstract

Brain-evoked muscle-action potential (Br (E)-MsEP) is useful method of the intraoperative spinal cord monitoring. In the intraoperative monitoring during spinal surgery, in the influence of anesthetizing and other general conditions should be considered. Although we usually monitor the muscle of the upper extremity as the reference waveform in thoracic and lumber spine surgery, there is no reference waveform in cervical spine surgery. The aim of this study was to evaluation of utility of the electromyogram of sternocleidomastoideus (SCM) and diaphragm (DP) as the reference waveform in the intraoperative monitoring using Br (E)-MsEP. In ten patients during spinal surgery, we monitor the electromyogram of SCM and DP. In all patients, the electromyograms of SCM and DP were able to be recorded but we could not detect onset point of SCM at all due to interference of stimulation waveform. On the other hand, the onset latencies of DP were 17.8 ± 1.9 (mean ± SD) ms. The peak-to-peak amplitudes of SCM and DP were 607.5 ± 329.3 μV and 366.2 ± 264.1 (mean ± SD) μV respectively. Our findings suggest that DP may become a reference waveform of the intraoperative monitoring during cervical spine surgery.