Abstracts

Rationale: The goal of the present study is to use a novel computational source reconstruction algorithm, i.e., variation-based sparse cortical current density (VB-SCCD) method, to noninvasively reconstruct epileptogenic zones from the external magnetoencephalography (MEG) in patients with intractable epilepsy. The availability of the non-invasive technology is paramount valuable for the pre-surgical planning in epilepsy, as compared with the current invasive procedure in clinics. Methods: Three patients with medically refractory epilepsy were studied. Each of patients received an MRI scan of the head. High density MEG was spontaneously recorded for 10-20 minutes with 148-channel whole-head magnetometer (Magnes WH2500, 4-D Neuroimaging, San Diego, CA, USA) in a magnetically shield room. 24, 58, 30 interictal spikes were selected, marked and analyzed respectively for three patients, and results were confirmed by experienced neurologists. The performance was evaluated by comparing with non-invasively imaged epileptogenic zones and those identified by lesional MRI, as well as presurgical evaluation outcomes. Results: Our results suggest that the reconstructed cortical sources behind interictal spikes using VB-SCCD are consistent with presurgical diagnosis of cortical tubers and outcomes of resection in terms of location in all three patients and in all studied interictal spikes (figure 1). The spatial distributions of cortical sources in each patient are consistent across multiple different interictal spikes. Conclusions: The present study shows the promising capability of the novel VB-SCCD method in non-invasively estimating locations of epileptogenic zones underlying interictal spikes with external magnetic signal.