Data from: Temporal lobe epilepsy: hippocampal pathology modulates white matter connectome topology and controllability

OBJECTIVE. To assess whether HS severity is mirrored at the level of
large-scale networks. METHODS. We studied preoperative high-resolution
anatomical and diffusion-weighted MRI of 44 TLE patients with
histopathological diagnosis of HS (n=25; TLE-HS) and isolated gliosis
(n=19; TLE-G), and 25 healthy controls. Hippocampal measurements included
surface-based subfield mapping of atrophy and T2 hyperintensity indexing
cell loss and gliosis, respectively. Whole-brain connectomes were
generated via diffusion tractography and examined using graph theory along
with a novel network control theory paradigm which simulates functional
dynamics from structural network data. RESULTS. Compared to controls, we
observed markedly increased path length and decreased clustering in TLE-HS
compared to controls, indicating lower global and local network
efficiency, while TLE-G showed only subtle alterations. Similarly, network
controllability was lower in TLE-HS only, suggesting limited range of
functional dynamics. Hippocampal imaging markers were positively
associated with macroscale network alterations, particularly in
ipsilateral CA1-3. Systematic assessment across several networks revealed
maximal changes in the hippocampal circuity. Findings were consistent when
correcting for cortical thickness, suggesting independence from grey
matter atrophy. CONCLUSIONS. Severe HS is associated with marked
remodeling of connectome topology and structurally-governed functional
dynamics in TLE, as opposed to isolated gliosis which has negligible
effects. Cell loss, particularly in CA1-3, may exert a cascading effect on
brain-wide connectomes, underlining coupled disease processes across
multiple scales.