Combining interictal intracranial EEG and fMRI to compute a dynamic resting-state index for surgical outcome validation
Combining interictal intracranial EEG and fMRI to compute a dynamic resting-state index for surgical outcome validation

Combining interictal intracranial EEG and fMRI to compute a dynamic resting-state index for surgical outcome validation

Front Netw Physiol. 2025 Jan 28;4:1491967. doi: 10.3389/fnetp.2024.1491967. eCollection 2024.

ABSTRACT

INTRODUCTION: Accurate localization of the seizure onset zone (SOZ) is critical for successful epilepsy surgery but remains challenging with current techniques. We developed a novel seizure onset network characterization tool that combines dynamic biomarkers of resting-state intracranial stereoelectroencephalography (rs-iEEG) and resting-state functional magnetic resonance imaging (rs-fMRI), vetted against surgical outcomes. This approach aims to reduce reliance on capturing seizures during invasive monitoring to pinpoint the SOZ.

METHODS: We computed the source-sink index (SSI) from rs-iEEG for all implanted regions and from rs-fMRI for regions identified as potential SOZs by noninvasive modalities. The SSI scores were evaluated in 17 pediatric drug-resistant epilepsy (DRE) patients (ages 3-15 years) by comparing outcomes classified as successful (Engel I or II) versus unsuccessful (Engel III or IV) at 1 year post-surgery.

RESULTS: Of 30 reviewed patients, 17 met the inclusion criteria. The combined dynamic index (im-DNM) integrating rs-iEEG and rs-fMRI significantly differentiated good (Engel I-II) from poor (Engel III-IV) surgical outcomes, outperforming the predictive accuracy of individual biomarkers from either modality alone.

CONCLUSION: The combined dynamic network model demonstrated superior predictive performance than standalone rs-fMRI or rs-iEEG indices.

SIGNIFICANCE: By leveraging interictal data from two complementary modalities, this combined approach has the potential to improve epilepsy surgical outcomes, increase surgical candidacy, and reduce the duration of invasive monitoring.

PMID:39936165 | PMC:PMC11811083 | DOI:10.3389/fnetp.2024.1491967