Group-level stability but individual variability of neurocognitive status after awake resections of right frontal IDH-mutated glioma

Abstract

Awake surgery for low-grade gliomas is currently considered the best procedure to improve the extent of resection and guarantee a "worth living life" for patients, meaning avoiding not only motor but also cognitive deficits. However, tumors located in the right hemisphere, especially in the right frontal lobe, are still rarely operated on in awake condition; one of the reasons possibly being that there is little information in the literature describing the rates and nature of long-lasting neuropsychological deficits following resection of right frontal glioma. To investigate long-term cognitive deficits after awake surgery in right frontal IDH-mutated glioma. We retrospectively analyzed a consecutive series of awake surgical resections between 2012 and 2020 for right frontal IDH-mutated glioma. We studied the patients' subjective complaints and objective neuropsychological evaluations, both before and after surgery. Our results were then put in perspective with the literature. Twenty surgical cases (including 5 cases of redo surgery) in eighteen patients (medium age: 42.5 [range 26–58]) were included in the study. The median preoperative volume was 37 cc; WHO grading was II, III and IV in 70%, 20%, and 10% of cases, respectively. Preoperatively, few patients had related subjective cognitive or behavioral impairment, while evaluations revealed mild deficits in 45% of cases, most often concerning executive functions, attention, working memory and speed processing. Immediate postoperative evaluations showed severe deficits of executive functions in 75% of cases but also attentional deficits (65%), spatial neglect (60%) and behavioral disturbances (apathy, aprosodia/amimia, emotional sensitivity, anosognosia). Four months after surgery, although psychometric z-scores were unchanged at the group level, individual evaluations showed a slight decrease of performance in 9/20 cases for at least one of the following domains: executive functions, speed processing, attention, semantic cognition, social cognition. Our results are generally consistent with those of the literature, confirming that the right frontal lobe is a highly eloquent area and suggesting the importance of operating these patients in awake conditions.

Electrostimulation of the white matter of the posterior insula and medial operculum: perception of vibrations, heat, and pain

“…Electrical stimulation was used as previously reported. 2,12,32,34 In brief, we made use of a bipolar probe (pole diameter 5 2 mm, interpole distance 5 7 mm), delivering a biphasic rectangular pulse of adjustable intensity (range: 2-3 mA) at a frequency of 60 Hz. The stimulation was applied for 3 to 4 seconds.…”

“…All patients underwent the previously described imaging protocol, 2,35 the day before, the day after, and 4 months after the surgery. Extent of resection was estimated on FLAIR sequences for lower-grade glioma and on 3D-T1 with gadolinium for glioblastoma.…”

Constant Multi-Tasking With Time Constraint to Preserve Across-Network Dynamics Throughout Awake Surgery for Low-Grade Glioma: A Necessary Step to Enable Patients Resuming an Active Life

“…In fact, even though intraoperative electrostimulation mapping has been shown to significantly decrease the rate of persistent hemiparesis and/or aphasia ( 5 ), higher-order functions have received less attention. However, recent studies have evidenced a frequency of cognitive declines higher than previously thought after glioma surgery, in one or several domains such as language, attention processing, executive functions and verbal memory ( 16 , 23 , 24 ) - including after tumor resection within so-called “non-eloquent” brain areas ( 25 ). In addition, postoperative mentalistic deficits and behavioral or personality changes have also been observed ( 18 , 26 , 27 ).…”