Change in Structural Connectivity Following Stereotactic Thermocoagulation in Mesial Temporal Lobe Epilepsy Patients.

Area of Science:

• Neurosurgery
• Epileptology
• Neuroscience

Background:

• Medically intractable temporal lobe epilepsy (MTLE) often requires surgical intervention.
• Understanding the relationship between resected brain regions, network alterations, and patient outcomes is crucial for optimizing surgical strategies.

Purpose of the Study:

• To investigate the association between the extent of postoperative lesions in specific brain regions and their impact on structural and functional brain connectivity.
• To correlate these network changes with patient outcomes following surgery for refractory MTLE.

Main Methods:

• Retrospective analysis of 21 patients with refractory unilateral MTLE undergoing surgery.
• Voxel-by-voxel calculation of ablated gray matter and affected fiber pathways (decrease in anisotropy).
• Graph theory analysis to compare pre- and postoperative structural and functional brain networks between seizure-free and non-seizure-free groups.

Main Results:

• Fifteen patients (71.42%) achieved seizure freedom at follow-up (12-48 months).
• The seizure-free group demonstrated significantly larger ablation volumes in the amygdala and rhinal cortex.
• Significant alterations in structural connectivity network metrics were observed in the seizure-free group compared to the non-seizure-free group.

Conclusions:

• Higher ablation volumes of the amygdala and rhinal cortex are associated with improved structural connectivity and better seizure control in MTLE.
• These findings offer insights into the role of brain connectivity networks in MTLE and may inform the development of improved SEEG-guided RFTC interventions.