Persistent white matter disruption underlies apparent functional normalization in intractable temporal lobe epilepsy:...

Area of Science:

• Neuroimaging
• Epilepsy Research
• Brain Function

Background:

• Intractable temporal lobe epilepsy (ITLE) presents significant treatment challenges.
• Existing neuroimaging studies show functional and structural brain abnormalities in ITLE.
• The combined impact of these abnormalities on treatment resistance is not well understood.

Purpose of the Study:

• To investigate the relationship between functional and structural brain changes in ITLE patients.
• To determine if these changes correlate with treatment refractoriness.
• To explore potential neuroimaging markers for ITLE treatment resistance.

Main Methods:

• Longitudinal resting-state fMRI (rs-fMRI) and diffusion tensor imaging (DTI) data were collected from ITLE patients (pre-/post-treatment) and healthy controls.
• Analysis included functional (ALFF/ReHo) and structural (FA/MD/AD/RD) feature extraction.
• Exploratory analyses utilized random-forest classification and UMAP visualization to compare discriminative patterns.

Main Results:

• Post-treatment, ITLE patients showed partial normalization of functional measures towards control levels.
• White matter abnormalities, particularly reduced fractional anisotropy in the Fornix (crus)/Stria terminalis, persisted post-treatment.
• Exploratory classification revealed that structural features distinguished ITLE from controls even after treatment, while functional features often misclassified post-treatment ITLE as healthy, indicating a structural-functional dissociation.

Conclusions:

• Persistent white matter microstructural alterations may underlie treatment resistance in ITLE, despite functional normalization.
• The observed structural-functional dissociation provides quantitative support for distinct pathological mechanisms.
• Machine learning and visualization techniques may aid in identifying and validating future therapeutic targets for ITLE.