Nimg-42lower Brain Network Efficiency in Idh1 Wild Type (idh-wt) Malignant Astrocytoma Compared to Idh1 Mutant (idh1-m)
Year: 2015
Type: article
Study design: Observational Study
Abstract: We previously demonstrated that patients with IDH1-WT compared to IDH1-M malignant astrocytoma exhibited worse cognitive function. We hypothesized that this is due to greater lesion momentum that may preclude compensatory brain reorganization. Therefore, in the present study, we examined the structural connectome of patients with IDH1-M and -WT tumors to determine if brain network organization differed between these patient groups. Volumetric, T1 MRI scans were evaluated retrospectively from 15 IDH1-M and 15 IDH1-WT. There were no differences between groups in terms of age, sex or education. Groups did not differ in tumor laterality but IDH1-M demonstrated less incidence of glioblastoma (p = .025), more frequent temporal lobe tumor location (p = .036) and moderately larger tumor volumes (p = .10). Discrete cortical and subcortical gray matter volumes were extracted from the MRI for each subject and cross-correlated across subjects to create an association matrix for each group. Matrices were corrected for tumor volume and histology. Graph theory was applied to these matrices to construct a large-scale structural brain network, or "connectome" for each group. We then measured the connectome global efficiency (Geff) for each group. Geff is a measure of network organization pertaining to integration and information flow. Nonparametric permutation analysis indicated that Geff was significantly lower in the IDH1-WT group (Geff = .41) compared to IDH1-M (Geff = .59, p = .001). IDH1-WT also demonstrated less network hubs than IDH1-M suggesting disconnection of critical brain regions. In summary, brain network integration, efficiency and connectivity are lower in IDH1-WT tumor compared to IDH1-M. This finding was independent of tumor volume and histology. This may reflect the slower growth of the IDH1-M tumor, which may allow the brain time to adapt to the tumor's presence and reorganize critical neurocircuitry.
Source: Neuro-Oncology
Institution: The University of Texas MD Anderson Cancer Center
Language: English
Subfield: Cognitive Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2561640458