Asymmetric tumor-related alterations of network-specific intrinsic functional connectivity in glioma patients.

Abstract

Resting‐state functional MRI (rs‐fMRI) allows mapping temporally coherent brain networks, and intra‐ and inter‐network alterations have been described in different diseases. This prospective study investigated hemispheric resting‐state functional connectivity (RSFC) differences in the default‐mode network (DMN) and fronto‐parietal network (FPN) between patients with left‐ and right‐hemispheric gliomas (LH PAT, RH PAT), addressing asymmetry effects the tumor might have on network‐specific intrinsic functional connectivity under consideration of the prognostically relevant isocitrate‐dehydrogenase (IDH) mutation status. Twenty‐seven patients (16 LH PAT, 12 IDH‐wildtype) and 27 healthy controls underwent anatomical and rs‐fMRI as well as neuropsychological assessment. Independent component analyses were performed to identify the DMN and FPN. Hemispheric DMN‐ and FPN‐RSFC were computed, compared across groups, and correlated with cognitive performance. Patient groups did not differ in tumor volume, grade or location. RH PAT showed higher contra‐tumoral DMN‐RSFC than controls and LH PAT. With regard to the FPN, contra‐tumoral RSFC was increased in both patient groups as compared to controls. Higher contra‐tumoral RSFC was associated with worse cognitive performance in patients, which, however, seemed to apply mainly to IDH‐wildtype patients. The benefit of RSFC alterations for cognitive performance varied depending on the affected hemisphere, cognitive demand, and seemed to be altered by IDH‐mutation status. At the time of study initiation, a clinical trial registration was not mandatory at our faculty, but it can be applied for if requested.