2011 AES Annual Meeting - 501.01 - Scientific Plenary: EEG and MEG Source Imaging in Epilepsy: Which is Better?
Program Length: 90 minutes
Source imaging is based on the integration of temporal and spatial components of electroencephalography (EEG) or magnetoencephalography (MEG) using mathematical modeling techniques to characterize cortical generators noninvasively. An interpretation of EEG and MEG source imaging requires an understanding of the differences and limitations of each technique. MEG requires smaller sources and the magnetic fields are less affected by the resistive inhomogenieties of the brain, skull, and scalp, but it is insensitive to radial components of the source. MEG data, therefore, tends to be more focal and easier to model. Technical and clinical validation of MEG source imaging have been demonstrated extensively in the past decade. EEG, on the other hand, requires larger sources and is sensitive to both radial and tangential components of the source and, therefore, measures activity from cortical gyri, as well as sulci and fissures. However, the electric fields are distorted and attenuated by the resistive properties of the skull and scalp. Recent advances in computational capability have made EEG source imaging more accurate and less time consuming and have enhanced interest in its clinical role. To date, the validity and clinical utility of EEG source imaging in focal epilepsy remains largely under-studied. This symposium will review the relative strengths and weaknesses of EEG and MEG source imaging in the localization of epileptogenic foci. Other clinical applications of source imaging, such as cortical mapping, will also be explored.
- Use newly acquired information regarding the relative strengths and weaknesses of EEG and MEG source imaging in evaluation of patients being considered for surgery to improve treatment planning
- Utilize EEG and / or MEG source imaging to define potential area of resection in presurgical evaluation of refractory focal epilepsy
- Apply results of EEG and MEG source imaging in presurgical functional mapping, improving the number of patients with successful outcomes regarding seizure and reducing potential complications of surgery.
Intermediate and Advanced (see page 98 for details)
Co-Chairs: Kitti Kaiboriboon, M.D., John S. Ebersole, M.D.
Introduction and Opening Remarks
Kitti Kaiboriboon, M.D.
The Pros and Cons of EEG and MEG Source Imaging
John S. Ebersole, M.D.
EEG Source Imaging in Epilepsy Evaluations
Thomas Bast, M.D.
MEG Source Imaging in the Presurgical Work-Up
Robert C. Knowlton, M.D., M.S.P.H.
Source Imaging in Mapping Eloquent Cortex
Samden D. Lhatoo, M.D., FRCP
John S. Ebersole, M.D.