COTREL-DUBOUSSET INSTRUMENTATION IN CHILDREN USING SIMULTANEOUS MOTORAND SOMATOSENSORY-EVOKED POTENTIAL MONITORING

Study Design. To record prospectively combined motor- and somatosensor y-evoked potentials in children during scoliosis surgery using Cotrel- Dubousset Instrumentation, without using special anesthetic or muscle relaxant regimens. Objective. To determine the outcome of scoliosis su rgery guided by a new technique of monitoring motor- and somatosensory -evoked potentials simultaneously. Summary of Background Data. Other t echniques used to assess cord function generally are limited by specia l anesthetic requirements or assess only a limited part of the cord or monitor motor function separately from somatosensory function. Method s. Spinal cord function was monitored using epidural leads to record s imultaneously the descending motor volley (by transcranial electrical stimulation) and the ascending somatosensory volley (by tibial nerve s timulation) at two spinal levels. Results. Combined motor- and sensory -evoked potentials were recorded successfully in 138 of 160 children ( 81%). Changes in evoked potential waveforms were seen in eight patient s (5%), but resolved or lessened in response to appropriate measures. Curve correction was satisfactory, and there were no new postoperative deficits or worsening of preexisting deficits in any patient. Conclus ion. A spinal cord monitoring system is described that is safe, reliab le, accurate, and makes it unnecessary to resort to the ''wake-up'' te st.