Presurgical Accuracy of Dipole Clustering in MRI-Negative Pediatric Patients with Epilepsy: Validation against Intracranial EEG and Resection

Abstract Objective To assess the utility of interictal magnetic and electric source imaging (MSI and ESI) using dipole clustering in magnetic resonance imaging (MRI)-negative patients with drug resistant epilepsy (DRE). Methods We localized spikes in low-density (LD-EEG) and high-density (HD-EEG) electroencephalography as well as magnetoencephalography (MEG) recordings using dipoles from 11 pediatric patients. We computed each dipole’s level of clustering and used it to discriminate between clustered and scattered dipoles. For each dipole, we computed the distance from seizure onset zone (SOZ) and irritative zone (IZ) defined by intracranial EEG. Finally, we assessed whether dipoles proximity to resection was predictive of outcome. Results LD-EEG had lower clusterness compared to HD-EEG and MEG (p Conclusion MSI and ESI dipole clustering helps to localize the SOZ and IZ and facilitate the prognostic assessment of MRI-negative patients with DRE. Significance Assessing the MSI and ESI clustering allows recognizing epileptogenic areas whose removal is associated with optimal outcome.