Intraoperative monitoring of motor-evoked potentials in children undergoing spinal surgery.

STUDY DESIGN: Clinical case series.

OBJECTIVE: To study the combined use of modifications of stimulation methods and adjustments of anesthetic regimens on the reliability of motor-evoked potential (MEP) monitoring in a large group of children undergoing spinal surgery.

SUMMARY OF BACKGROUND DATA: Monitoring of MEPs is advocated during spinal surgery, but systematic data from children are sparse.

METHODS: A total of 134 consecutive procedures in 108 children <18 years of age were analyzed. MEPs were elicited by transcranial electrical stimulation (TES) and supplemented by temporal and spatial facilitation. The standard anesthesia regimen consisted of propofol, nitrous oxide, and remifentanil. Propofol was replaced with ketamine if no reliable MEPs could be recorded. In children <6 years of age, a ketamine-based anesthesia was used.

RESULTS: With temporal facilitation alone, reliable MEPs were obtained in 78% (105 of 134) of the procedures and, if combined with spatial facilitation, in 96% (129 of 134) of the procedures. Reliable MEPs were documented in 98% (111 of 113) of children >6 years and in 86% (18 of 21) in children <6 years of age.

CONCLUSIONS: Combining spatial facilitation with a TES protocol improved monitoring of corticospinal motor pathways during spinal surgery in children. A ketamine-based anesthetic technique was preferred in children <6 years of age.