Altered Resting State Networks Before and After Temporal Lobe Epilepsy Surgery

Area of Science:

• Neuroimaging
• Epilepsy Research
• Brain Network Analysis

Background:

• Unilateral mesial temporal lobe epilepsy (mTLE) is characterized by alterations in resting state networks (RSNs).
• Understanding functional connectivity (FC) changes is crucial for assessing surgical outcomes in mTLE.

Purpose of the Study:

• To investigate alterations in RSNs in mTLE patients pre- and post-successful epilepsy surgery.
• To explore changes in FC within and between RSNs, and between the hippocampus and RSNs.

Main Methods:

• Resting-state functional MRI and T1-weighted structural MRI were used.
• 37 mTLE patients achieving seizure freedom post-anterior temporal lobectomy were scanned before and 2 years after surgery.
• 28 healthy controls were included for comparison.

Main Results:

• Pre-surgery, decreased FC was noted in visual and basal ganglia networks. Post-surgery, basal ganglia network FC further decreased, while sensorimotor and dorsal attention networks showed increased FC.
• Between-network FC alterations were observed, with increased FC related to the default mode network pre-surgery and visual/dorsal attention networks post-surgery.
• Hippocampal FC with RSNs showed significant changes pre-surgery, with normalization or no obvious changes observed post-surgery.

Conclusions:

• MTLE patients exhibit significant RSN alterations, with the basal ganglia network showing progressive FC decline.
• Successful epilepsy surgery appears to induce RSN reorganization and functional remodeling at a whole-brain-network level.
• These findings offer preliminary evidence for postoperative functional brain network changes in mTLE.