Analysis of Intraoperative Motor Evoked Potential Changes and Surgical Interventions in 513 Pediatric Spine Surgeries

Abstract

Purpose:(1) To determine probabilities of immediate postoperative new motor deficits after no, reversible, and irreversible motor evoked potentials (MEP) deteriorations and (2) to calculate the same outcome considering whether MEP deteriorations were followed by surgical interventions in the absence of confounding factors.Methods: We analyzed MEPs from 513 surgeries. Four-limb MEPs were evoked by transcranial electrical stimulation. Baseline recordings were obtained before skin incision and updated before instrumentation. Motor evoked potentials deteriorations were considered significant whenever they showed a persistent, reversible, or irreversible amplitude decrease of .80% of the baseline values.Results: Nine patients showed postoperative new motor deficits. Probabilities of postoperative new motor deficits were null, 2.8%, and 36.8% with no, reversible, and irreversible MEP deteriorations, respectively. The risk of immediate postoperative new motor deficits was significantly lower (P ¼ 0.0002) in reversible MEP compared with irreversible MEP deteriorations. In patients showing reversible/irreversible MEP deteriorations in the absence of confounding factors, surgical interventions compared with nonsurgical interventions significantly decreased the risk of immediate postoperative new motor deficits (P ¼ 0.0216).Conclusions: This study shows that probabilities of immediate postoperative new motor deficits increase with the severity of intraoperative MEP changes. In addition, our results support the value of surgical interventions triggered by MEP deteriorations to reduce postoperative adverse motor outcomes.

Impact of low-dose sevoflurane with propofol-based anaesthesia on motor-evoked potentials in infants: protocol for a single-centre randomised controlled study

“…The stimulating electrodes of a pair of 20 mm plated disks will be placed with conductive paste at 1–2 cm anterior sites of C3 (cathode) and C4 (anode) on the international 10-20 system, targeting the motor cortex area in infants. 9 A train of five to eight square-wave pulses will be delivered at an interval of 2.0 m/s at a stimulation frequency of 0.9 Hz. The intensity of stimulation will be determined during the first TcMEP recording for control data, where the intensity was set supramaximal to each stimulus (ie, 300–600 V).…”