Intraoperative Experience With Neuromotor Evoked Potentials: A Review of 60 Consecutive Cases

STUDY DESIGN.A review of 60 surgical cases for correction of scoliosis, during which neuromotor evoked potentials and somatosensory evoked potentials were monitored. OBJECTIVES.To determine the validity and reliability of intraoperative neuromotor evoked potential monitoring in cases of scoliosis, where damage to the motor tracts of the spinal cord can occur. SUMMARY OF BACKGROUND DATA.Recently, the validity of neuromotor evoked potentials monitoring has been challenged, suggesting that the responses are not necessarily neuromotor evoked responses, but a combination of neuromotor and somatosensory evoked responses. This theory rendered the responses a potentially invalid measure of motor ability. However, despite controversy surrounding this topic, many professionals consider neuromotor evoked potential monitoring to be a successful and reliable measure of motor spinal cord function. METHODS.The results of neuromotor evoked potential testing were reviewed in 60 consecutive cases of children who underwent surgery for scoliosis. A standard protocol described in 1995 by Owen was used. RESULTS.Clinically useful neuromotor evoked potentials were obtained for 54 patients (90%). Inability to obtain neuromotor evoked potentials occurred in six patients (10%). CONCLUSIONS.This two-part study demonstrated the efficacy and reliability of neuromotor evoked potential monitoring during scoliosis surgery and examined the sources of difficulty in achieving accurate and valid results.