Functional Connectivity Predicts Epilepsy Surgery Outcomes
Publication Title: Spatial and spectral structure of local functional connectivity of the background intracranial EEG in patients with focal epilepsy
Summary
- Question
- This study investigated how specific patterns of brain connectivity, referred to as band-related local functional connectivity (BRLFC), in patients with focal epilepsy relate to the seizure onset area (SOA) and how these patterns might predict outcomes of epilepsy surgery. The researchers focused on differences in connectivity across various brain wave frequency bands and their spatial relationship to the SOA.
- Why it Matters
- Focal epilepsy is a condition where seizures originate in a specific part of the brain. For patients whose seizures cannot be controlled by medication, surgery to remove the SOA can be an effective treatment. However, predicting surgical outcomes remains challenging. This study's findings could help identify markers in the brain's connectivity patterns that indicate better surgical outcomes, potentially improving patient selection for surgery and understanding the mechanisms underlying epilepsy.
- Methods
- The researchers studied 14 adult patients with focal epilepsy who underwent intracranial electroencephalogram (icEEG) monitoring as part of their pre-surgical evaluation. Using electrodes implanted in the brain, they recorded one-hour segments of brain activity during periods when patients were on anti-seizure medications (ASMs) and after ASMs were tapered off. They measured BRLFC in different frequency bands, such as delta (slow brain waves) and gamma (fast brain waves), and analyzed its relationship to the distance from the SOA.
- Key Findings
- Patients who experienced excellent surgical outcomes showed distinct patterns of connectivity. In these patients, BRLFC was highest in the peri-SOA (areas within 5 cm of the SOA) in high-frequency bands like gamma and beta, and this connectivity decreased with distance from the SOA. These patterns were not observed in patients with poor surgical outcomes. Notably, these connectivity profiles were stable regardless of whether patients were on or off ASMs.
- Implications
- The findings suggest that BRLFC in specific frequency bands could serve as a biomarker for identifying epileptic networks and predicting surgical success. High BRLFC in the peri-SOA may indicate areas critical to seizure generation and propagation, guiding more precise surgical targeting. This approach could refine epilepsy surgery planning and enhance understanding of epilepsy as a network disorder.
- Next Steps
- The authors propose further studies with larger patient groups to validate their findings and explore how BRLFC can be used to optimize surgical planning. They also suggest investigating whether BRLFC can be applied to other brain disorders or used as a tool to track epilepsy development over time.
- Funding Information
- This research was supported by funding from the Swebilius Trust. Yale University also provided funding and support for this research.
Full Citation
Zaveri H, Pincus S, Goncharova I, Munbodh R, Hirsch L, Duckrow R, Spencer D. Spatial and spectral structure of local functional connectivity of the background intracranial EEG in patients with focal epilepsy. Frontiers In Network Physiology 2026, 5: 1441949. PMID: 41584435, PMCID: PMC12827612, DOI: 10.3389/fnetp.2025.1441949.
This AI-assisted summary has been reviewed and approved by at least one of the study's authors to ensure it accurately reflects the research.
Authors
Hitten Zaveri, PhD
First AuthorProfessor of Neurology, Pediatrics and Neurosurgery
Dennis D. Spencer
Last Author