Resting state network plasticity related to picture naming in low-grade glioma patients before and after resection.

The dynamic connectome perspective states that brain functions arise from the functional integration of distributed and/or partly overlapping networks. Diffuse low-grade gliomas (DLGG) have a slow infiltrating character. Here we addressed whether and how anatomical disconnection following DLGG growth and resection might interfere with functional resting-state connectivity, specifically in relation to picture naming. Thirty-nine native French persons with a left DLGG were included. All underwent awake surgical resection of the tumor using direct brain electrostimulation to preserve critical eloquent regions. The anatomical disconnectivity risk following the DLGG volume and the resection, and the functional connectivity of resting-state fMRI images in relation to picture naming were evaluated prior to and three months after surgery. Resting-state connectivity patterns were compared with nineteen healthy controls. It was demonstrated that picture naming was strongly dependent on the semantic network that emerged from the integration and interaction of regions within multiple resting-state brain networks, in which their specific role could be explained in the light of the broader resting-state network they take part in. It emphasized the importance of a whole brain approach with specific clinical data input, during resting-state analysis in case of lesion. Adaptive plasticity was found in secondary regions, functionally connected to regions close to the tumor and/or cavity, marked by an increased connectivity of the right and left inferior parietal lobule with the left inferior temporal gyrus. In addition, an important role was identified for the superior parietal lobe, connected with the frontal operculum, suggesting functional compensation by means of attentional resources in order to name a picture via recruitment of the frontoparietal attention network.

Peri- and intraoperative cognitive and language assessment for surgical resection in brain eloquent structures.

Neuropsychological care of patients suffering from an infiltrative glioma and candidates for a neurosurgery under awake condition with intraoperative functional mapping is a critical and mandatory stage in therapeutic management. It enables to estimate the functional impact of the tumor and, consequently, the efficacy of functional reorganization typically observed in these patients, not only to better predict surgery outcomes and select appropriate tasks for intraoperative functional mapping, but also to plan efficient and individualized postoperative cognitive rehabilitation strategies. Neuropsychological care management also enables patients to benefit from a solid psychological preparation both to the surgery and its associated transitory functional consequences, as well as provide a personalized psychological and emotional long-term support. Based on their solid experience in the peri-operative care of diffuse low-grade glioma patients, the authors thoroughly describe the different stages of neuropsychological management. Cognitive, emotional and language assessments typically used by the authors around and during surgery are reported, and different possible avenues of improvement are further discussed.

Surgical resection of incidental diffuse gliomas involving eloquent brain areas. Rationale, functional, epileptological and oncological outcomes.

OBJECTIVE: Incidentally discovered diffuse low-grade gliomas progress in a fashion similar to their symptomatic counterparts. Their early detection allows more effective pre-emptive and individualized oncological treatment. We assessed the safety and efficacy of maximal safe resection according to functional boundaries for incidental diffuse low-grade gliomas in eloquent areas. MATERIAL AND METHODS: Two-centre retrospective series of adult patients with incidental diffuse low-grade gliomas located within/close to eloquent areas in the dominant hemisphere, treated with maximal surgical resection according to functional boundaries under intraoperative functional cortico-subcortical monitoring under awake conditions, and with a minimal follow-up of 24months. RESULTS: The series included 19 patients (8 men, 11 women) with no preoperative neurological deficit but with a radiologically enlarged glioma. No intraoperative seizure, postoperative infection, haematoma or wound-healing problem was observed. In the immediate postsurgical period, a transient neurological worsening occurred in 10 patients. The resection (mean rate 96.4%; range, 82.4-100) was supratotal in 5 cases, total in 5 cases, subtotal in 7 cases, and partial in 2 cases. Six months after surgery, all patients recovered after functional rehabilitation, with no permanent neurological deficit, Karnofsky Performance Status was 100 (except for one patient who received early postoperative radiotherapy) and no seizures were observed. The survival without progression requiring oncological treatment was significantly longer in patients with a total/supratotal resection than in patients with a partial/subtotal resection. CONCLUSIONS: These results suggest the reproducibility, safety, and effectiveness of an early maximal functionally based resection within cortico-subcortical functional boundaries for incidental diffuse low-grade gliomas in adults in centres hyperspecialized in surgical neuro-oncology.