Altered structural connectome in temporal lobe epilepsy.

Area of Science:

• Neuroscience
• Medical Imaging
• Epilepsy Research

Background:

• Epilepsy, particularly temporal lobe epilepsy (TLE), is a neurological disorder characterized by recurrent seizures.
• Understanding the underlying brain network alterations in TLE is crucial for developing targeted therapies.

Purpose of the Study:

• To investigate whole-brain structural connectome differences between patients with left TLE and healthy controls.
• To identify specific network alterations associated with left TLE.

Main Methods:

• Diffusion-tensor imaging (DTI) and MP-RAGE MRI were used to analyze brain structure in 24 left TLE patients and 24 healthy controls.
• Structural connectivity matrices were generated using white matter tractography, and graph theoretical measures were applied.
• Connectivity networks were compared between groups using linear models and permutation testing.

Main Results:

• Patients with TLE exhibited significantly reduced distant connectivity (22%-45%) in areas including the medial orbitofrontal cortex, temporal cortex, posterior cingulate cortex, and precuneus.
• Conversely, local connectivity, measured by network efficiency, was significantly increased (85%-270%) in frontal, insular, posterior cingulate, precuneus, and occipital cortices.
• These findings indicate widespread network reorganization in TLE.

Conclusions:

• Left TLE is associated with significant alterations in structural brain connectivity extending beyond the temporal lobe.
• The default mode network appears to be particularly affected, suggesting its involvement in the pathophysiology of TLE.
• These findings highlight the network-based nature of TLE and may inform future therapeutic strategies.