Highlights Large and homogenous sample of patients with insula-centered low-grade gliomas. Functional connectivity of the contralesional insula compared with healthy controls. Inter-insular connectivity decreased. Functional connectivity increased towards bilateral visual and sensorimotor networks. Homotopic redistribution of the functional connectivity in brain-damaged patients.

Background and purposeThe aim of this longitudinal study is to evaluate large-scale perioperative resting state networks reorganization in patients with diffuse low-grade gliomas following awake surgery.Materials and methodsEighty-two patients with diffuse low-grade gliomas were prospectively enrolled and underwent awake surgical resection. Resting-state functional images were acquired at three time points: preoperative (MRI-1), immediate postoperative (MRI-2) and three months after surgery (MRI-3). We simultaneously performed perfusion-weighted imaging.ResultsComparing functional connectivity between MRI-1 and MRI-2, we observed a statistically significant functional homotopy decrease in cortical and subcortical supratentorial structures (P < 0.05). A functional homotopy increase was observed between MRI-2 and MRI-3 in parietal lobes, cingulum and putamen (P < 0.05). No significant functional connectivity modification was noticed between MRI-1 and MRI-3. Regional cerebral blood flow appeared transiently reduced on MRI-2 (P < 0.05). No correlation between neurological deficit and interhemispheric connectivity results was found.Conclusion/interpretationWe found a supratentorial widely distributed functional homotopy disruption between preoperative and immediate postoperative time points with a complete restitution three months after surgery with simultaneous variation of regional cerebral blood flow.