Imaging structural and functional brain networks in temporal lobe epilepsy.

Area of Science:

• Neuroscience
• Medical Imaging
• Epileptology

Background:

• Early temporal lobe epilepsy (TLE) research focused on mesial temporal sclerosis, with surgery improving outcomes for ~70% of patients.
• A significant portion of patients experience persistent post-operative seizures, suggesting factors beyond localized lesions.
• Emerging evidence points to TLE as a disorder of distributed brain networks, necessitating a broader perspective.

Purpose of the Study:

• To review the application of advanced neuroimaging techniques in analyzing structural and functional brain networks in TLE.
• To highlight findings from graph-theoretical analysis in understanding TLE network topology.
• To explore the potential of network properties as clinical diagnostic markers for TLE.

Main Methods:

• Utilizing non-invasive neuroimaging methods to quantify in vivo structural and functional brain networks.
• Employing diffusion MRI tractography and cortical thickness covariance for structural network inference.
• Analyzing functional connectivity through statistical dependencies in neurophysiological time-series (fMRI, EEG).
• Applying graph-theoretical analysis to assess the topological organization of brain networks.

Main Results:

• Compelling evidence demonstrates TLE as a system disorder with significant alterations in local and distributed brain networks.
• Structural and functional network analyses reveal profound changes in network organization.
• Graph-theoretical approaches highlight topological abnormalities in TLE networks.

Conclusions:

• Temporal lobe epilepsy is fundamentally a disorder of distributed brain networks, not solely a focal lesion.
• Network alterations in TLE extend beyond the temporal lobe and impact surgical outcomes.
• Network properties show promise as valuable clinical diagnostic markers for TLE, essential for understanding its development, progression, and management.