Structural connectivity of the ANT region based on human ex-vivo and HCP data. Relevance for DBS in ANT for epilepsy

•We suspect that competing network (sub-) components are causative for the heterogeneous outcome of DBS for focal epilepsy when implanting “the ANT region”.•The high-resolution fiber atlas of the ANT region serves as basis for patient-specific whole brain modeling of such networks.•This work implements a synthetic pathway reconstruction method by combining anatomical fiber tracking with dMRI-based tractography.•Extended connectivity is based on the combination of structural, functional and topographic network features.•An anatomical high-resolution fiber map is introduced that represents the most important bundles related to the ANT region.•Our approach, based on microscale evaluation and assessment of neighborhood relations, optimizes the descriptive and predictive validity of parcellated structures. Deep Brain Stimulation (DBS) in the Anterior Nucleus of the Thalamus (ANT) has been shown to be a safe and efficacious treatment option for patients with Drug-Resitant focal Epilepsy (DRE). The ANT has been selected frequently in open and controlled studies for bilateral DBS. There is a substantial variability in ANT-DBS outcomes which is not fully understood. These outcomes might not be explained by the target location alone but potentially depend on the connectivity of the mere stimulation site with the epilepsy onset-associated brain regions. The likely sub-components of this anatomy are fiber pathways which penetrate or touch the ANT region and constitute a complex and dense fiber network which has not been described so far. A detailed characterization of this ANT associated fiber anatomy may therefore help to identify which areas are associated with positive or negative outcomes of ANT-DBS. Furthermore, prediction properties in individual ANT-DBS cases might be tested. In this work we aim to generate an anatomically detailed map of candidate fiber structures which might in the future lead to a holistic image of structural connectivity of the ANT region. To resolve the various components of the complex fiber network connected to the ANT we used a synthetic pathway reconstruction method that combines anatomical fiber tracking with dMRI-based tractography and iteratively created an anatomical high-resolution fiber map representing the most important bundles related to the ANT. The anatomically detailed 3D representation of the fibers in the ANT region generated with the synthetic pathway reconstruction method incorporates multiple anatomically defined fiber