The structure-function dissociation in mesial temporal lobe epilepsy with temporopolar blurring.

OBJECTIVES

While ipsilateral temporopolar blurring (TPB) has been associated with white matter degeneration in temporal lobe epilepsy with hippocampal sclerosis (TLE-HS), its influence within the large-scale neural networks remains unclear. This study investigates the network-level topological alterations associated with TPB through multilayer network analysis.

METHODS

This retrospective study investigated the impact of TPB on topological architecture of structural (SCN) and functional connectivity networks (FCN) in patients with TLE-HS using graph theory analysis. We further calculated the weighted multiplex participation coefficient (wMxP) to quantify the SCN-FCN interaction in a multiplex connectome.

RESULTS

In total, 105 patients with TLE-HS (60 TPB+; 45 TPB-) and 61 healthy controls were enrolled. We found similar global network organization but altered nodal topological properties between TPB+ and TPB- in single-layer analysis, predominantly across the default mode network, visual network, and subcortical ROIs. Additionally, TPB+ showed decreased average wMxP (t(df=97) = -2.265, p < 2.2e-16) and lower nodal wMxP in default mode network and ipsilateral thalamus (t(df=97)=-2.404, pfwer=0.0408) than those in TPB-.

CONCLUSIONS

We demonstrate that disrupted topological architecture associated with TPB in TLE-HS were primarily and locally distributed in brain regions with rich connections to the temporal pole. The dissociation between SN and FN may indicate compensatory functional adjustments in TLE.