Clinical and methodological advances in EEG-fMRI for epilepsy: a focused review

Simultaneous EEG-fMRI is a unique, noninvasive neuroimaging technique that enables high spatial resolution mapping of metabolic changes linked to EEG epileptic discharges in focal and generalized epilepsy, reflected through fMRI signals. It is increasingly recognized as a valuable tool in the presurgical evaluation of drug-resistant epilepsy, supporting the localization of epileptogenic zones, guiding electrode implantation, and informing surgical strategies and outcome prediction, while also revealing important insights into the networks involved in epileptic activity. Advances in artifact removal, automated spike detection, and statistical modeling have improved EEG-fMRI's data quality and clinical utility. It is particularly valuable in diagnostically challenging cases where standard EEG is not localizing, or MRI findings are negative. However, its routine clinical adoption is limited by the complexity of the procedure, the lack of standardized protocols, interpretation criteria, and broader validation across diverse epilepsy populations. This review highlights EEG-fMRI's evolving role in localizing epileptic discharges, emphasizing both methodological and clinical aspects. It covers the process from data acquisition through analysis to statistical interpretation and decision-making, with its application in distinguishing generalized from widespread activity, assessing thalamic involvement in focal epilepsy, evaluating status epilepticus, mapping blood oxygen-level dependent responses in relation to structural lesions, and supporting presurgical planning in complex cases, demonstrating its potential to improve diagnostic precision and treatment outcomes.