Fixel-wise reductions of thalamic fiber integrity in new onset epilepsy and drug-resistant temporal lobe epilepsy

Motivation: Axonal changes that occur throughout epileptogenesis and early-stage epilepsy remain unclear. Goal(s): We aimed to identify and relate diffusion weighted MRI changes in the thalamus of patients with new onset epilepsy and patients with long term drug-resistant temporal lobe epilepsy. Approach: We compared diffusion MRI at different orientations within each voxel (fixels) in the thalamus of patients with new onset epilepsy, temporal lobe epilepsy, and healthy controls. Results: We found that patients with new onset epilepsy trended towards reductions in fiber integrity of the right ventral thalamus, similar to those of patients with drug-resistant temporal lobe epilepsy. Impact: Our results suggest that ventral thalamus fibers may be damaged in temporal lobe epilepsy and this damage could be detectable in early-stage epilepsy. These results may have implications for thalamic neurostimulation and future studies of progression in new onset epilepsy.