Clinical Application of MEG Source Localization Algorithms in Presurgical Epilepsy Evaluation: Strengths and Limitations

Abstract

Event Abstract Back to Event Clinical Application of MEG Source Localization Algorithms in Presurgical Epilepsy Evaluation: Strengths and Limitations Douglas Rose1*, Hisako Fujiwara1, Nat Hemasilpin1, Ki Lee1 and Francesco Mangano1 1 University of Cincinnati, Cincinnati Children's Hospital Medical Center, United States MEG source localization algorithms perform well in simulation studies with low noise; little is known regarding relative strengths and limitations of algorithms for real clinical data. We compared algorithms with a common presurgical evaluation clinical dataset. We recorded MEG interictal discharges for 209 patients (ages 1 mo–26 years) with medically intractable epilepsy. We analyzed all recordings with equivalent current dipole models (ECD) and a beamformer, synthetic aperture magnetometry (SAM). We additionally analyzed recordings in 50 patients with dipole scan (DS), (multiple signal classification -MUSIC) and distributed dipole models (DD) (minimum norm estimate - MNE, standardized low resolution brain electromagnetic tomography - sLORETA). We compared each to presurgical scalp interictal/ictal EEG findings. We compared MEG to ECoG localization for 59 patients who had ECD and SAM only and for 17 patients studied with all 5 algorithms. For ECD and DD we had to carefully choose representative samples with low background noise. Use of segmented cortical mantle improved localization for ECD, DS, and DD, but also introduced potential errors. DD tended to localize a single contiguous source region for each patient. SAM tended to identify multiple locations and gave reasonable localizations in the presence of VNS artifact (24 patients) but failed to localize spikes under several conditions. Use of several methodologies limited errors from each; when multiple algorithms indicated a similar region, the localization more often agreed with ictal onset by ECoG. MEG source localization algorithms highlight different aspects of the irritative zone associated with interictal discharges based on different a priori assumptions and different approaches to the inverse problem. Use of several different MEG source localization methodologies may improve localization non-invasively of the irritative zone prior to placement of intracranial electrodes and prior to epilepsy surgery. Conference: Biomag 2010 - 17th International Conference on Biomagnetism , Dubrovnik, Croatia, 28 Mar - 1 Apr, 2010. Presentation Type: Poster Presentation Topic: Epilepsy Citation: Rose D, Fujiwara H, Hemasilpin N, Lee K and Mangano F (2010). Clinical Application of MEG Source Localization Algorithms in Presurgical Epilepsy Evaluation: Strengths and Limitations. Front. Neurosci. Conference Abstract: Biomag 2010 - 17th International Conference on Biomagnetism . doi: 10.3389/conf.fnins.2010.06.00377 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 08 Apr 2010; Published Online: 08 Apr 2010. * Correspondence: Douglas Rose, University of Cincinnati, Cincinnati Children's Hospital Medical Center, Cincinnati, United States, douglas.rose@cchmc.org Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Douglas Rose Hisako Fujiwara Nat Hemasilpin Ki Lee Francesco Mangano Google Douglas Rose Hisako Fujiwara Nat Hemasilpin Ki Lee Francesco Mangano Google Scholar Douglas Rose Hisako Fujiwara Nat Hemasilpin Ki Lee Francesco Mangano PubMed Douglas Rose Hisako Fujiwara Nat Hemasilpin Ki Lee Francesco Mangano Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.