Retrospective analysis of hemispheric structural network change as a function of location and size of glioma

Abstract

Gliomas are neoplasms that arise from glial cell origin and represent the largest fraction of primary malignant brain tumours (77%). These highly infiltrative malignant cell clusters modify brain structure and function through expansion, invasion and intratumoral modification. Depending on the growth rate of the tumour, location and degree of expansion, functional reorganization may not lead to overt changes in behaviour despite significant cerebral adaptation. Studies in simulated lesion models and in patients with stroke reveal both local and distal functional disturbances, using measures of anatomical brain networks. Investigations over the last two decades have sought to use diffusion tensor imaging tractography data in the context of intracranial tumours to improve surgical planning, intraoperative functional localization, and post-operative interpretation of functional change. In this study, we used diffusion tensor imaging tractography to assess the impact of tumour location on the white matter structural network. To better understand how various lobe localized gliomas impact the topology underlying efficiency of information transfer between brain regions, we identified the major alterations in brain network connectivity patterns between the ipsilesional versus contralesional hemispheres in patients with gliomas localized to the frontal, parietal or temporal lobe. Results were indicative of altered network efficiency and the role of specific brain regions unique to different lobe localized gliomas. This work draws attention to connections and brain regions which have shared structural susceptibility in frontal, parietal and temporal lobe glioma cases. This study also provides a preliminary anatomical basis for understanding which affected white matter pathways may contribute to preoperative patient symptomology.

Network analysis shows decreased ipsilesional structural connectivity in glioma patients

“…This result suggests that higher WHO grade gliomas are more likely to impair the cortico-subcortical connections regardless of their location, thus further reinforcing the idea that patterns of altered structural connectivity depend on the WHO grade (10,69). As earlier studies have demonstrated local effects of gliomas on their surrounding microstructural integrity of the WM (70,71), we aimed at investigating whether glioma locations may affect unique subsets of nodes and edges in the ipsilesional network. While gliomas affect brain regions and connections near the lesion, brain connectivity changes may also occur distally from the lesion, either because of the resulting local dysconnectivity or as a neuroplasticity mechanism taking place during tumor growth.…”

“…Reduced global and local efficiency reflect the impairment of information transfer across different regions of derived networks, which is likely linked to the pathological involvement of both long- and short-range connections. In contrast with these findings, a recent publication showed increased global and local efficiency in the ipsilesional hemispheric network, identifying unique sets of nodes with changes in network efficiency depending on lesion location ( 71 ).…”

“…As earlier studies have demonstrated local effects of gliomas on their surrounding microstructural integrity of the WM ( 70, 71 ), we aimed at investigating whether glioma locations may affect unique subsets of nodes and edges in the ipsilesional network. While gliomas affect brain regions and connections near the lesion, brain connectivity changes may also occur distally from the lesion, either because of the resulting local dysconnectivity or as a neuroplasticity mechanism taking place during tumor growth.…”

Network topology in brain tumor patients with and without structural epilepsy- a prospective MEG-study

“…It was previously described that different kinds of neurological disorders, such as brain tumors lead to deviations in the brain’s functional network (Cho et al, 2021; D’Souza et al, 2021; Huang et al, 2014; Hyder et al, 2021; Na et al, 2018).…”

Modified Diffusion Tensor Image Processing Pipeline for Archived Studies of Patients With Leukoencephalopathy

“…The benefit of this is to achieve the research goal quickly and cost effectively. Previous retrospective studies have utilized existing DWI data sets to investigate late radiation‐induced damages after focal radiotherapy, 1 hemispheric structural network changes as a function of location and size of glioma, 2 and even the relationship between reading performance and white matter (WM) alteration and reorganization in neurosurgical patients 3 . In addition, as more and more archived data become publicly available, research can be conducted efficiently if the data can be processed in an appropriate way.…”