Neurosurgery for eloquent lesions in children: state-of-the-art rationale and technical implications of perioperative neurophysiology

Abstract

OBJECTIVE In adult patients, an increasing group of neurosurgeons specialize entirely in the treatment of highly eloquent tumors, particularly gliomas. In contrast, extensive perioperative neurophysiological workup for pediatric cases has been limited essentially to epilepsy surgery. METHODS The authors discuss radio-oncological and general oncological considerations based on the current literature and their personal experience. RESULTS While several functional mapping modalities facilitate preoperative identification of cortically and subcortically located eloquent areas, not all are suited for children. Direct cortical intraoperative stimulation is impractical in many young patients due to the reduced excitability of the immature cortex. Behavioral requirements also limit the utility of functional MRI and magnetoencephalography in children. In contrast, MRI-derived tractography and navigated transcranial magnetic stimulation are available across ages. Herein, the authors review the oncological rationale of function-guided resection in pediatric gliomas including technical implications such as personalized perioperative neurophysiology, surgical strategies, and limitations. CONCLUSIONS Taken together, these techniques, despite the limitations of some, facilitate the identification of eloquent areas prior to tumor surgery and radiotherapy as well as during follow-up of residual tumors.

Advances in the Treatment of Pediatric Brain Tumors

“…Stereotaxis has streamlined minimally invasive approaches to biopsy intracranial lesions, especially those in subcortical locations. Transcranial magnetic stimulation, coupled with functional MRI (fMRI), allows for preoperative motor and language mapping for children in whom direct cortical stimulation during awake surgery is not feasible [19,20].…”