Introduction: We investigated the efficacy of combined somatosensory evoked potentials (SSEP) and electromyography monitoring during paddle lead placement through cervicothoracic laminectomy under general anesthesia in a retrospective review of data from 25 patients.

Methods: Muscle motor evoked potentials (MEP) recordings and SSEP monitoring were used for surveillance of the spinal cord. Collision testing of SSEP and threshold amplitudes of compound muscle action potentials (CMAP) in the bilateral upper and lower extremities evoked by electrode contacts of the paddle lead were checked to determine the laterality of the lead in the mediolateral direction.

Results: A significant decrease in amplitudes of muscle MEP in spite of stable SSEP occurred in 2 patients: 1 patient with a retrograde C1–C2 insertion and another patient with an anterograde C4/C5 insertion. Repositioning of leads based on significantly asymmetrical collision testing of SSEP and thresholds of CMAP in bilateral extremities was needed in 6 and 8 patients, respectively. In 22 patients, paresthesia coverage of the painful area was consistently located in the painful side, either unilaterally or bilaterally. There was no episode of revision for suboptimal lead placement.

Conclusions: Intraoperative neurophysiological guidance using SSEP and muscle MEP was useful for the safe and accurate placement of paddle leads for cervicothoracic SCS.

Patient Care: This research will improve surgical outcome of paddle lead placement for cervicothoracic spinal cord stimulation by reducing complications during surgery.

Learning Objectives: By the conclusion of this session, participants should be able to identify usefulness of SSEP and muscle MEP during paddle lead placement for cervicothoracic SCS

References: Deletis V, Sala F: Intraoperative neurophysiological monitoring of the spinal cord during spinal cord and spine surgery: a review focus on the corticospinal tracts. Clin Neurophysiol 2008; 119: 248–264.