A functional MRI study of presurgical cognitive deficits in glioma patients

Abstract

Background The main goal of this functional MRI (fMRI) study was to examine whether cognitive deficits in glioma patients prior to treatment are associated with abnormal brain activity in either the central executive network (CEN) or default mode network (DMN). Methods Forty-six glioma patients, and 23 group-matched healthy controls (HC) participated in this fMRI experiment, performing an N-back task. Additionally, cognitive profiles of patients were evaluated outside the scanner. A region of interest based analysis was used to compare brain activity in CEN and DMN between groups. Post-hoc analyses were performed to evaluate differences between low grade glioma (LGG) and high grade glioma (HGG) patients. Results In-scanner performance was lower in glioma patients compared to HC. Neuropsychological testing indicated cognitive impairment in LGG as well as HGG patients. FMRI results revealed normal CEN activation in glioma patients, whereas patients showed reduced DMN deactivation compared to HC. Brain activity levels did not differ between LGG and HGG patients. Conclusions Our study suggests that cognitive deficits in glioma patients prior to treatment are associated with reduced responsiveness of the DMN, but not with abnormal CEN activation. These results suggest that cognitive deficits in glioma patients reflect a reduced capacity to achieve a brain state necessary for normal cognitive performance, rather than abnormal functioning of executive brain regions. Solely focusing on increases in brain activity may well be insufficient if we want to understand the underlying brain mechanism of cognitive impairments in patients, as our results indicate the importance of assessing deactivation.

Comparing end-tidal CO2, respiration volume per time (RVT), and average gray matter signal for mapping cerebrovascular reactivity amplitude and delay with breath-hold task BOLD fMRI

“…In a recent study of 10 healthy adults , 3 subjects were excluded due to poor CO 2 data quality. There are added difficulties with cooperation in patient cohorts, particularly in those with cognitive impairments who may struggle to execute commands ( Pujol et al, 1998 ;Schouwenaars et al, 2021 ). Obtaining highquality data in younger participants also tends to be more challenging, with inconsistent performance of breathing tasks reported among children and adolescents .…”

BOLD Coupling between Lesioned and Healthy Brain Is Associated with Glioma Patients’ Recovery

“…Glioblastomas reduce the complexity of functional activity not only within and close to the tumour but also at long ranges [ 21 ]. Alterations of functional networks before glioma surgery have been associated with increased cognitive deficits independent of any treatment [ 22 ]. One potential mechanism of tumoural tissue influencing neuronal activity and thus cognitive performance is through alterations in oxygenation level and cerebral blood volume [ 23 ].…”

T2 FLAIR Hyperintensity Volume Is Associated With Cognitive Function and Quality of Life in Clinically Stable Patients With Lower Grade Gliomas

“…These significant associations are of particular interest as they are noted even on tests for which the group as a whole performed normally, indicating that individual differences in T2 FLAIR hyperintensity volumes vary with cognitive performance. Even in clinically stable patients, larger tumor volume may cause more disruption of functional networks, and alterations in structural and functional connectivity have been associated with cognitive function in glioma (36)(37)(38)(39)(40)(41).…”