Large-scale cortico-subcortical functional networks in focal epilepsies: The role of the basal ganglia

This publication doesn't include Faculty of Arts. It includes Central European Institute of Technology. Official publication website can be found on muni.cz.

Authors

VÝTVAROVÁ Eva MAREČEK Radek FOUSEK Jan STRÝČEK Ondřej REKTOR Ivan

Year of publication 2017
Type Article in Periodical
Magazine / Source NeuroImage-Clinical
MU Faculty or unit

Central European Institute of Technology

Citation
Web http://www.sciencedirect.com/science/article/pii/S2213158216302510?via%3Dihub
Doi http://dx.doi.org/10.1016/j.nicl.2016.12.014
Field Neurology, neurosurgery, neurosciences
Keywords Functional magnetic resonance imaging; Functional connectivity; Epilepsy; Network analysis; Partial least square analysis
Description Objectives: The aimwas to describe the contribution of basal ganglia (BG) thalamo-cortical circuitry to thewholebrain functional connectivity in focal epilepsies. Methods: Interictal resting-state fMRI recordings were acquired in 46 persons with focal epilepsies. Of these 46, 22 had temporal lobe epilepsy: 9 left temporal (LTLE), 13 right temporal (RTLE); 15 had frontal lobe epilepsy (FLE); and 9 had parietal/ occipital lobe epilepsy (POLE). There were 20 healthy controls. The completeweighted networkwas analyzed based on correlation matrices of 90 and 194 regions. The network topologywas quantified on a global and regional level by measures based on graph theory, and connection-level changes were analyzed by the partial least square method. Results: In all patient groups except RTLE, the shift of the functional network topology away from random was observed (normalized clustering coefficient and characteristic path length were higher in patient groups than in controls). Links contributing to this change were found in the cortico-subcortical connections. Weak connections (low correlations) consistently contributed to thismodification of the network. The importance of regions changed: decreases in the subcortical areas and both decreases and increases in the cortical areas were observed in node strength, clustering coefficient and eigenvector centrality in patient groups when compared to controls. Node strength decreases of the basal ganglia, i.e. the putamen, caudate, and pallidum, were displayed in LTLE, FLE, and POLE. The connectivity within the basal ganglia-thalamus circuitry was not disturbed; the disturbance concerned the connectivity between the circuitry and the cortex. Significance: Focal epilepsies affect large-scale brain networks beyond the epileptogenic zones. Cortico-subcortical functional connectivity disturbance was displayed in LTLE, FLE, and POLE. Significant changes in the restingstate functional connectivity between cortical and subcortical structures suggest an important role of the BG and thalamus in focal epilepsies.
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