Drug-refractory epilepsy (DRE) may be treated by surgical intervention. Intracranial EEG has been widely used to localize the epileptogenic zone (EZ). Most studies of epileptic network focus on the features of EZ nodes, such as centrality and degrees. It is difficult to apply those features to the treatment of individual patients. In this study, we proposed a spatial neighbor expansion approach for EZ localization based on a neural computational model and epileptic network reconstruction. The virtual resection method was also used to validate the effectiveness of our approach. The electrocorticography (ECoG) data from 11 patients with DRE were analyzed in this study. Both interictal data and surgical resection regions were used. The results showed that the rate of consistency between the localized regions and the surgical resections in patients with good outcomes was higher than that in patients with poor outcomes. The average deviation distance of the localized region for patients with good outcomes and poor outcomes were 15 mm and 36 mm, respectively. Outcome prediction showed that the patients with poor outcomes could be improved when the brain regions localized by the proposed approach were treated. This study provides a quantitative analysis tool for patient-specific measures for potential surgical treatment of epilepsy.
For patients with MRI-negative drug-resistant epilepsy, noninvasive localization of targets for transcranial electrical stimulation (tES) remains a clinical challenge. This study proposes a novel target localization approach that integrates electroencephalogram source imaging, brain network analysis, and a neural computational model. We analyzed electrocorticography (ECoG) data from 12 patients, quantified the epileptogenicity of epileptic network nodes, and noninvasively located optimal stimulation targets. Three source imaging methods and two brain network reconstruction measures were compared for localization performance. Among four patients with good outcomes, the method accurately localized epileptogenic tissues in three. Results of tES simulation demonstrated that cathodal direct current stimulation of the target region significantly reduced the brain network's epileptogenicity. This study provides a noninvasive, quantifiable targeting strategy for tES therapy in epilepsy patients.
