EEG & MEG Source Imaging in Epilepsy: Which is Better?

EEG & MEG Source Imaging in Epilepsy: Which is Better? December 6, 2011 Co-Chairs Kitti Kaiboriboon, MD Assistant Professor of Neurology University Hospitals Case Medical Center John S. Ebersole, MD Professor and Co-Director Comprehensive Epilepsy Center University of Chicago American Epilepsy Society Annual Meeting

Disclosure Nothing to disclose. American Epilepsy Society Annual Meeting

Epilepsy Research Benchmarks Area II: Develop new therapeutic strategies and optimize current approaches to cure epilepsy. A.Identify basic mechanisms of ictogenesis (seizure generation) that will lead to the development of cures. 2. Define the functional networks in the brain that are responsible for seizure generation in clinical epilepsy using biosensors, imaging and other methods. C.Optimize existing therapies and develop new therapies and technologies for curing epilepsy. 1. Determine factors and approaches associated with best outcomes for surgical therapies. http://www.ninds.nih.gov/research/epilepsyweb

Learning Objectives Understand the relative strengths and weaknesses of EEG and MEG source imaging. Increase the awareness of the utility of EEG and/or MEG source imaging in presurgical evaluation of refractory focal epilepsy. Appreciate the value of EEG and MEG source imaging in presurgical functional mapping. American Epilepsy Society Annual Meeting

EEG & MEG Source Imaging in Epilepsy: Which is Better? The Pros & Cons of EEG and MEG Source Imaging John S. Ebersole, M.D. University of Chicago, Chicago, IL EEG Source Imaging in Epilepsy Evaluations Thomas Bast, M.D. Epilepsy Center Kork, Germany MEG Source Imaging in the Presurgical Work-Up Robert C. Knowlton, M.D., M.S.P.H. University of Alabama, Birmingham, AL Source Imaging in Mapping Eloquent Cortex Samden D. Lhatoo, M.D., FRCP University Hospitals Case Medical Center, Cleveland, OH

History Timeline of EEG & MEG 1875: First attempt of EEG recording 1924: Human EEG recording Gibbs-Gibbs-Lennox Era 1934: EEG in epilepsy 1935: Grass Model I Normal EEG and its variant Sleep EEG pattern 1947: American EEG Society Hans Berger (1873-1941)

History Timeline of EEG & MEG 1875: First attempt of EEG recording 1924: Human EEG recording Gibbs-Gibbs-Lennox Era 1934: EEG in epilepsy 1935: Grass Model I Normal EEG and its variant Sleep EEG pattern 1947: American EEG Society 1968: First MEG recording 1969: Biomagnetic SQUID measurement 1972: MEG using SQUID 1977: MEG in epilepsy Edelsack, Cohen, & Zimmerman The MIT shielded room December 1969 1984: Multi-channels SQUID 1992: Whole-head MEG system 2006: American Clinical MEG Society [Cohen, Neurology & Clinical Neurophysiology 2004:114]

Inverse Problem Dipole Model Distributed Model

Forward Problem Spherical Head Model Realistic Head Model

Which Solution Should Be Chosen? EEG- Forward Solution: Realistic Head >> Spherical Shell EEG- Inverse Solution: Dipole Model = Distributed Model MEG- Forward Solution: Spherical Shell = Realistic Head MEG- Inverse Solution: Dipole Model = Distributed Model [Ebersole. J Clin Neurophysiol 1999:201] [Plummer. J. Clin Neurophysiol 2010:141] [Shiraishi. J Clin Neurophysiol 2011:431]

EEG & MEG Source Imaging 1875: First attempt of EEG recording 1924: Human EEG recording Gibbs-Gibbs-Lennox Era 1934: EEG in epilepsy 1935: Grass Model I Normal EEG and its variant Sleep EEG pattern 1947: American EEG Society 1949: First study of dipole 1968: First MEG recording 1969: Biomagnetic SQUID measurement 1972: MEG using SQUID 1977: MEG in epilepsy 1984: Multi-channels SQUID [Helmholtz. Annalen der Physik 1853;165(6)] 1992: Whole-head MEG system 2006: American Clinical MEG Society

EEG & MEG Source Imaging 1875: First attempt of EEG recording 1924: Human EEG recording Gibbs-Gibbs-Lennox Era 1934: EEG in epilepsy 1935: Grass Model I Normal EEG and its variant Sleep EEG pattern 1947: American EEG Society 1949: First study of dipole 1968: First MEG recording 1969: Biomagnetic SQUID measurement 1972: MEG using SQUID 1977: MEG in epilepsy 1984: Multi-channels SQUID 1992: Whole-head MEG system 2006: American Clinical MEG Society

Source Imaging Software Software Website ASA Brain Electrical Source Analysis (BESA) Brainstorm CURRY EEGLAB econnectome EMSE Suite FieldTrip MNE software NUTMEG Statistical Parametric Mapping (SPM) SimBio http://www.ant-neuro.com/products/asa/source http://www.besa.de/ http://neuroimage.usc.edu/brainstorm/introduction http://www.neuroscan.com/curry.cfm http://sccn.ucsd.edu/eeglab/ http://econnectome.umn.edu/ http://www.sourcesignal.com/ http://fieldtrip.fcdonders.nl/start http://www.nmr.mgh.harvard.edu/martinos/userinfo/data/sofmne.php http://nutmeg.berkeley.edu/index.php?title=main_page http://www.fil.ion.ucl.ac.uk/spm/ https://www.mrt.uni-jena.de/simbio/index.php/main_page

PubMed Search For ESI & MSI