Related Experiment Video
Updated: Aug 6, 2026
Translational Brain Mapping at the University of Rochester Medical Center: Preserving the Mind Through Personalized Brain Mapping
Published on: August 12, 2019
Addressing connectomic constraints in early practice of awake-guided neurosurgery: a four-year prospective
Sam Ng1,2, Andrea Otamendi-Lopez3, Basile Martin3
1Department of Neurosurgery, Gui de Chauliac Hospital, Montpellier University Medical Center, 80 Avenue Augustin Fliche, 34090, Montpellier, France. s-ng@chu-montpellier.fr.
Purpose:
Awake functional-guided resection (AFGR) is the gold-standard approach in glioma surgery. The learning curve associated with mastering white matter tracts (WMT) identification using direct electrostimulation (DES) mapping remains poorly characterized. The goal of this study was to compare subcortical DES mapping performance between early-career and expert neurosurgeons.
Methods:
In this prospective, monocentric, case-matched study, patients undergoing AFGR (2022-2025) were operated on either by an early-career neurosurgeon during the first four years of independent practice (cohortA) or by a senior expert neurosurgeon with extensive experience in awake mapping procedures (cohortB). DES-elicited responses were compared using multivariable multinomial regression, adjusting for histology and anatomical location. WMT identification rates were analyzed using a benchmark-normalized Relative Detection Efficiency (RDE).
Results:
Overall, 352 AFGR procedures were analyzed, including 101 in cohortA. Histology differed between cohorts, with fewer IDH-mutant grade 2 gliomas (46.5% vs 65.3%) and more glioblastomas (27.7% vs 6.4%) in cohortA. Postoperative tumor volume and functional outcomes were comparable. A total of 1,158 DES responses were recorded. Negative motor responses were more frequent in cohortA (+ 11.3%[95%CI:3.3-18.9], P = 0.006), whereas semantic paraphasia tended to be less frequent (- 15.4%[95%CI: - 32.3-0.6], P = 0.079). Identification of the inferior fronto-occipital fasciculus was reduced in cohortA, particularly in left frontal approaches (RDE:0.53[95%CI:0.31-0.81], P = 0.002), consistent with comparable overall extents of resection (EOR) except in frontal tumors.
Conclusion:
Benchmarking early-career practice of AFGR against expert practice reveals selective, tract- and functional system-specific differences in DES mapping strategies, with minimal impact on EOR and similar functional outcomes. These findings suggest that AFGR is reliably implementable during early independent practice and support a dynamic connectomic constraint framework to guide training.
