White matter structural connectivity changes correlate with epilepsy duration in temporal lobe epilepsy

Area of Science:

• Neuroimaging
• Epilepsy Research
• White Matter Integrity

Background:

• Temporal lobe epilepsy (TLE) is increasingly viewed as a network disorder.
• Diffusion tensor imaging (DTI) has identified structural changes in TLE.
• Lateralized differences and disease duration effects on structural integrity remain underexplored.

Purpose of the Study:

• To investigate lateralized differences in white matter structural integrity in TLE.
• To examine how disease duration impacts structural integrity.
• To identify diffusion imaging markers for TLE laterality.

Main Methods:

• Examined fractional anisotropy (FA) and mean diffusivity (MD) in hippocampus and its connections (cingulum, fornix, uncinate, external capsule) in left and right TLE.
• Correlated diffusion measures with epilepsy duration to assess disease progression.
• Utilized random forest (RF) analysis to identify predictors of TLE laterality.

Main Results:

• Increased MD observed bilaterally in hippocampus, cingulum, fornix, and right external capsule in TLE patients compared to controls.
• Left TLE showed increased MD in ipsilateral uncinate fasciculus and bilateral external capsules; decreased FA in left cingulum.
• RF analysis identified right hippocampus MD and left external capsule FA as key predictors of TLE laterality.

Conclusions:

• Demonstrated disrupted white matter architecture in TLE affecting hippocampus and its connections.
• Hippocampal and cingulum changes were more pronounced in right TLE, while remote connection changes were more prominent in left TLE.
• Right hippocampus MD and left external capsule FA are strong predictors of TLE laterality, suggesting potential for DTI in diagnosis and prognosis.