In our latest paper we show that in glioma patients connections between different brain areas are affected on a broad scale. Specifically connections linked to brain regions that play a central role in information processing (hubs) are altered.
By analysing 71 functional MRI scans of glioma (brain tumor) patients and a cohort of healthy controls we first made a ‘connectomic profile’ of all the functional connections in the brain (connections are based on brain regions that show similar activation patterns). The connectomic profile represents the distribution of the strength of all the connections between all brain regions. This analysis showed us that the profile of glioma patients was different from healthy controls, such that patients had less variance in the distribution of connection strengths than their matched healthy controls. By taking a closer look at the type of connections that might be altered in brain tumor patients, we found that specifically connections linked to brain areas that play a central role in the brain, the so-called hubs, were impacted, but in a differential manner. Connections between hub areas were decreased in brain tumor patients and connections between hub areas and other regions showed an increase in connectivity compared to healthy controls. Next, we investigated what the clinical relevance was of these different features. We found that the connectomic profile differed between types of glioma malignancy. Also, in the case of the most malignant tumor type, the connectomic profile was a predictor for progression of the tumor.
These new findings show us the impact of a tumor on global brain functioning and that hubs have a special and complex role in this process. From a clinical point of view, the results underscore the promise of using connectomics as a future biomarker in brain tumor patients.