Awake Mapping With Transopercular Approach in Right Insular–Centered Low-Grade Gliomas Improves Neurological Outcomes and Return to Work

Asleep vs awake surgery for right insula-centered low-grade glioma (LGG) is still debated.To compare neurological outcomes and return to work after resection for right insular/paralimbic LGG performed without vs with awake mapping.A personal surgical experience of right insula-centered LGG was analyzed, by comparing 2 consecutive periods. In the first period (group 1), patients underwent asleep surgery with motor mapping. In the second period (group 2), patients underwent intraoperative awake mapping of movement and cognitive functions.This consecutive series included 143 LGGs: 41 in group 1 (1999-2009) and 102 in group 2 (2009-2020). There were no significant difference concerning preoperative clinicoradiological characteristics and histopathology results between both groups. Intraoperative motor mapping was positive in all cases in group 1. In group 2, beyond motor mapping, somatosensory, visuospatial, language, and/or cognitive functions were identified during cortical-subcortical stimulation. Postoperatively, 3 patients experienced a long-lasting deterioration with 2 hemiparesis due to deep stroke (1.3%) and 1 severe depressive syndrome, all of them in group 1 vs none in group 2 (P = .022). The rate of RTW was 81.5% in group 1 vs 95.5% in group 2 (P = .016). The tumor volume and extent of resection did not significantly differ across both groups.This is the first study comparing asleep vs awake surgery for right insula-centered LGG. Despite similar extent of resection, functional outcomes were significantly better in awake patients by avoiding permanent neurological impairment and by increasing RTW. These results support the mapping of higher-order functions during awake procedure.