Editorial: Use of intraoperative monitoring in children

Abstract

The holy grail of intraoperative monitoring is accurate correlation of electrophysiological changes and postoperative neurological changes. Ideally, feedback provided to the surgeon in real time would allow for an alteration in technique and thus the opportunity to prevent or reverse neurological deficits. While intraoperative neuromonitoring modalities continue to evolve, the perfect predictive value of this tool remains elusive. Intraoperative spinal cord monitoring is essentially the standard of care for adults harboring intramedullary tumors.5–7 Less information is available in the pediatric population, perhaps given the rarity of these lesions.2–4 Cheng et al.1 report on their experience using both transcranial motor evoked potentials (TcMEPs) and somatosensory evoked potentials (SSEPs) in a retrospective series of 12 patients. Overall, they found that intraoperative electrical changes predicted postoperative neurological outcomes. They correlated changes in TcMEP and SSEP monitoring with specific intraoperative maneuvers, including traction on the spinal cord and tumor resection via the cavitational ultrasonic surgical aspirator. They also used dorsal column mapping to accurately predict where to perform a midline myelotomy, novel information in the pediatric population. Several patients in the series had intraoperative changes in their monitoring, which correlated with new postoperative deficits. Not all of these deficits resolved, and the correlation between intraoperative changes and postoperative dysfunction was not perfect. While the use of intraoperative monitoring in children undergoing intramedullary spinal cord tumor resection appears to be useful, the results of this study must be interpreted with some caution. The study is retrospective in nature with only 12 patients, 5 of whom did not undergo dorsal column mapping. Data were collected over a period of 8 years, and the last patient in the series underwent surgery a decade ago. Moreover, D-wave monitoring,8–10 a more recent advance in the intraoperative assessment of motor function, was not utilized. Nevertheless, the data contribute to our understanding of spinal cord tumor resection in the pediatric population. The authors noted that raising the blood pressure above normal was not helpful in reversing SSEP changes and that releasing traction proved the most reliable maneuver for correcting the first SSEP change. Finally, the provided data offer some guidance in the intraoperative balancing act faced by every surgeon regarding how aggressive the tumor resection should be to avoid tumor recurrence, while doing no harm in preserving neurological function. (http://thejns.org/doi/abs/10.3171/2013.9.PEDS13439)