Resting-State Electroencephalography Functional Connectivity Networks Relate to Pre- and Postoperative Language Functioning in Low-Grade Glioma and Meningioma Patients

Abstract

Introduction: Preservation of language functioning in patients undergoing brain tumor surgery is essential because language impairments negatively impact the quality of life. Brain tumor patients have alterations in functional connectivity (FC), the extent to which brain areas functionally interact. We studied FC networks in relation to language functioning in glioma and meningioma patients.Method: Patients with a low-grade glioma (N = 15) or meningioma (N = 10) infiltrating into/pressing on the language-dominant hemisphere underwent extensive language testing before and 1 year after surgery. Resting-state EEG was registered preoperatively, postoperatively (glioma patients only), and once in healthy individuals. After analyzing FC in theta and alpha frequency bands, weighted networks and Minimum Spanning Trees were quantified by various network measures.Results: Pre-operative FC network characteristics did not differ between glioma patients and healthy individuals. However, hub presence and higher local and global FC are associated with poorer language functioning before surgery in glioma patients and predict worse language performance at 1 year after surgery. For meningioma patients, a greater small worldness was related to worse language performance and hub presence; better average clustering and global integration were predictive of worse outcome on language function 1 year after surgery. The average eccentricity, diameter and tree hierarchy seem to be the network metrics with the more pronounced relation to language performance.Discussion: In this exploratory study, we demonstrated that preoperative FC networks are informative for pre- and postoperative language functioning in glioma patients and to a lesser extent in meningioma patients.

Structural Reorganization Following a Brain Tumor: A Machine Learning Study Considering Desynchronized Functional Oscillations

“…To try and compensate, BOLD correlations between regions would rearrange themselves to spare the functionality. Network similarities and topologies across subjects would change, as found by previous studies [1, 2, 36, 3], without significantly altering their complexity. However, DASs could not disentangle whether the tumor altered the signal and that alteration spread to the DMN or the opposite.…”

“…The integrity of resting-state activity of the brain has been associated with cognitive function [6]. Based on this paradigm, numerous studies have explored how functional damage translates into cognitive impairment [4, 5, 1, 35, 3]. As a clear demonstration of the resilience of the brain to damage, all of them reported a continuous rather than binary decrease in cognitive performance.…”

“…For this purpose, we designed a Dynamics Alteration Score (DAS) that can capture not only how different two power distributions are, but also how these differences are related with the relative dynamics of those signals (see Methods; see also The integrity of resting-state activity of the brain has been associated with cognitive function [6]. Based on this paradigm, numerous studies have explored how functional damage translates into cognitive impairment [4,5,1,36,3]. As a clear demonstration of the resilience of the brain to damage, all of them reported a continuous rather than binary decrease in cognitive performance.…”

“…Brain networks undergo rearrangement to minimize the impact of lesions, and this rewiring follows specific constraints [24,36]. From electroencephalography recordings, Wolthuis and colleagues found the level of topological similarity to be predictive of post-surgery cognitive skills [35], suggesting once again that understanding how the brain responds to lesions is crucial to predict the impact of surgical procedures on cognitive function. To this purpose, we computed the complexity of the DMN and found significant alterations in magnitude with variable directionality across patients.…”

Functional and structural reorganization in brain tumors: a machine learning approach using desynchronized functional oscillations

“…The integrity of resting-state activity of the brain has been associated with cognitive function 6 . Based on this paradigm, numerous studies have explored how functional damage translates into cognitive impairment 1 , 3 – 5 , 35 . As a clear demonstration of the resilience of the brain to damage, all of them reported a continuous rather than binary decrease in cognitive performance.…”