Abstract
During the last decade multiple work has been done to determine the sources of epileptiform activity by means of dipole source localization based on recordings of the magnetoencephalogram (MEG) or the electroencephalogram (EEG). The actual available advanced volume conductor models and the multiple source reconstruction by regularization may give new impulse to EEG based source analyses in epilepsy patients. This study demonstrates the principal properties of these techniques. We applied two different EEG source reconstruction techniques within different volume conductor models to localize induced spike activity in a selected patient suffering from medically intractable temporal lobe epilepsy: 1) single moving dipole solution in a 3-shell spherical model versus individual head models (boundary-element-model, BEM, and finite-element-model, FEM); 2) a regularization technique for current density reconstructions using both BEM and FEM. When compared to findings of invasive recordings no adequate source locations were derived from the moving dipole solution in both the 3-shell head model and BEM. In contrast, a high congruence of source reconstruction and invasive determination of the focus was obtained using the regularization techniques in both BEM and FEM, indicating the high spatial accuracy of this technique in individual head models.
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Alarcon, G., Guy, C.N., Binnie, C.D., Walker, S.R., Elwes, R.D.C. and Polkey, C.E. Intracerebral propagation of interictal activity in partial epilepsy: implications for source localization. J. Neurol. Neurosurg. Psychiatry, 1994, 57: 435–449.
Barth, D.S., Sutherling, W.W., Engel, J.J. and Beatty, J. Neuromagnetic localization of epileptiform spike activity in the human brain. Science, 1982, 218: 891–894.
Brockhaus, A., Lehnertz, K., Wienbruch, C., Kowalik, A., Burr, W., Elbert, T., Hoke, M. and Elger, C.E. Possibilities and limitations of magnetic source imaging of methohexital-induced epileptiform patterns in temporal lobe epilepsy patients. Electroenceph. Clin. Neurophysiol., 1997, 102: 423–436.
Buchner, H., Waberski, T.D., Fuchs, M., Drenckhahn, R., Wagner, M. and Wischmann, H.-A. Postcentral origin of P22: evidence from source reconstruction in a realistically shaped head model and from a patient with a postcentral lesion. Electroenceph. Clin. Neurophysiol., 1996, 100: 332–342.
Buchner, H., Knoll, G., Fuchs, M., Rienäcker, A., Beckmann, R., Wagner, M., Silny, J. and Pesch, J. Inverse localization of electric dipole current sources in finite element models of the human head. Electroenceph. Clin. Neurophysiol., 1997, 102: 267–278.
Cohen, D. and Cuffin, B.N. Demonstration of useful differences between magnetencephalogram and electrencephalogram. Electroenceph. Clin. Neurophysiol., 1983, 56: 38–51.
Cohen, D., Cuffin, B.N., Yunokuchi, K., Maniewski, R., Purcell, C., Cosgrove, G.R., Ives, J., Kennedy, J.G. and Schomer, D.L. MEG versus EEG localization test using implanted sources in the human brain. Ann. Neurol., 1990, 28: 811–817.
Ebersole, J.S. EEG dipole modelling in complex partial epilepsy. Brain Topography, 1991, 4(2): 113–123.
Ebersole, J.S. and Wade, P.B. Spike voltage topography and equivalent dipole localization in complex partial epilepsy. Brain Topography, 1990, 3(1): 21–33.
Ebersole, J.S. and Hawes, S.M. Improved focus localization with realistic head models validated by intracranial EEG. Abstract of ISBET 1997 Zurich, 1997, 50.
Engel, J. Jr. Surgical Treatment of the Epilepsies. Raven Press, New York, 1993: 740–742.
Eisenberg, H., Papanicolau, A. and Baumann, S. Magnetoencephalographic localization of interictal spike sources. J. Neurosurg., 1991, 74: 660–664.
Fuchs, M., Drenkhahn, R., Wischmann, H.-A. and Wagner, M. An improved boundary element method for realistic volume coductor modeling. IEEE Trans. Biomed. Eng., 1997, in press.
Gedes, L.A. and Baker, L.E. The specific resistance of biological material — A compendium of data for the biomedical engineer and physiologist. Med. And Biol. Engng., 1963, Vol. 5: 271–293.
Gloor, P. Volume conductor principles: Their application to the surface and depth electroencephalogram. In: H.G. Wieser and C.E. Elger (Eds.), Presurgical Evaluation of Epileptics. Springer-Verlag, Berlin, 1987: 59–68.
Hämälainen, M.S. and Sarvas, J. Realistic conductivity geometry model of the human head for interpretation of neuromagnetic data. IEEE Trans. Biomed. Eng., 1989, 36(2): 165–171.
Hufnagel, A., Burr, W., Elger, C.E., Nadstawek, J. and Hefner, G. Localization of the epileptic focus during methohexital-induced anesthesia. Epilepsia, 1992, 3: 271–284.
Kolle, R., Herrendorf, G., Kurth, C., Steinhoff, B., Paulus, W., Waberski, T.D. and Buchner, H. Dipole source analysis of ictal and interictal EEG data of patients with temporal lobe epilepsy. Electroenceph. Clin. Neurophysiol., 1997, 103: 178.
Lantz, G., Holub, M., Ryding, E. and Rosén, I. Simultaneous intracranial and extracranial recording of interictal epileptiform activity in patients with drug resistant partial epilepsy: patterns of conduction and reults from dipole reconstructions. Electroenceph. Clin. Neurophysiol., 1996, 99: 69–78.
Lopes da Silva, H.J., Wieringa, H.J. and Peters, M.J. Source localization of EEG versus MEG: empirical comparison using visually evoked responses and theoretical considerations. Brain Topogr., 1991, 4: 133–142.
Mauguière, F. A consensus statement on relative merits of EEG and MEG. Electroenceph. Clin. Neurophysiol., 1992, 82: 317–319.
Modena, I., Ricci, G.B. and Barbanera, S. Biomagnetic measurements of spontaneus brain activity in epileptic patients. Electroenceph. Clin. Neurophysiol., 1982, 54: 622–628.
Paetau, R., Kajola, M., Karhu, J., Nousiainen, U., Partanen, J., Tiihonen, J., Vapalahti, M. and Hari, R. Magnetoencephalographic localization of epileptic cortex-Impact on surgical treatment. Ann. Neurol., 1992, 32: 106–109.
Paetau, M., Hämäläinen, R., Hari, R., Kajola, M., Karhu, J., Larsen, T.A., Lindahl, E. and Salonen, O. Magnetoencephalografic evaluation of children and adolescents with intractable epilepsy. Epilepsia, 1994, 35(2): 275–284.
Pascual-Marqui, R.D., Michel, C.M. and Lehmann, D. Low resolution electromagnetic tomography: a new method for localizing electrical activity in the brain. Int. J. Psychphysiol., 1994, 18(1): 49–65.
Pohlmeier, R., Buchner, H., Knoll, G., Rienäcker, A., Beckmann, R. and Pesch, J. The influence of skull-conductivity misspecification on inverse source localization in realistically shaped finite element head models. Brain Topography, 1997, 9: 157–162.
Ricci, G.B., Romani, G.L. and Salustri, C. Study of focal epilepsy by multichannel neuromagnetic measurements. Electroenceph. Clin. Neurophysiol., 1987, 66: 358–368.
Rose, D.F., Sato, S., Smith, P.D., Porter, R.J., Theodore, W.H., Friauf, W., Bonner, R. and Jabbari, B. Localization of magnetic interictal discharges in temporal lobe epilepsy. Ann. Neurol., 1987a, 22: 348–354.
Rose, D.F., Smith, P. and Sato, S. Magnetoencephalography and epilepsy research. Science, 1987b, 238: 329–335.
Roth, B.J., Balish, M., Gorbach, A. and Sato, S. How well does a three-sphere model predict positions of dipoles in a realistically shaped head? Electroenceph. Clin. Neurophysiol., 1993, 87(4): 175–184.
Stefan, H., Schneider, S., Abraham-Fuchs, K., Bauer, J., Fistel, H., Pawlik, G., Neubauer, U., Röhrlein, G. and Huk, W.J. Magnetic source localization in focal epilepsy. Brain, 1990, 113: 1347–1359.
Stefan, H. Clinical applications of MEG in epilepsy. Brain Topography, 1993, 5(4): 425–427.
Sutherling, W.W., Crandall, P.H., Cahan, L.D. and Barth, D.S. The magnetic field of interictal spikes agrees with intracranial localizations in complex partial epilepsy. Neurology, 1988, 38: 778–786.
Tiihonen, J., Hari, R. and Kajola, M. Localization of epileptic foci using a large-area magnetometer and functional brain anatomy. Ann. Neurol., 1989, 27: 283–290.
van der Meij, W., Wienecke, G.H. and van Huffelen, A.C. Dipole source analysis of rolandic spikes in benign rolandic epilepsy and other clinical syndromes. Brain Topography, 1993, 5(3): 203–213.
Waberski, T.D., Buchner, H., Kolle, R., Herrendorf, G., Beckmann, R., Wagner, M. Source localization of mesial-temporal epileptiform activity compared to foreward models. Electroenceph. Clin. Neurophysiol., 1997, 103: 196.
Wagner, M., Fuchs, M., Wischmann, H.-A., Ottenberg, K. and Dössel, O. Cortex segmentation from 3D MR images for MEG reconstructions. In: C. Baumgartner, L. Deecke, G. Stroink and S.J. Williamson (Eds.), Biomagnetism: Fundamental Research and Clinical Applications. IOS Press, Amsterdam, 1995: 433–438.
Wagner, M., Wischmann, H.-A., Fuchs, M., Köhler, T. and Drenckhahn, R. Current density reconstructions using the L1 norm. Proceedings of the BIOMAG 96, Santa Fe, New Mexico, 1997, in press.
Weinberg, H., Wong, P.K.H., Crisp, D., Johnson, B. and Cheyne, D. Use of multiple dipole analysis for the classification of benign rolandic epilepsy. Brain Topography, 1990, 2: 31–36.
Wong, P.K.H., Bencivenga, R. and Gregory, D. Statistical classification of spikes in benign rolandic epilepsy. Brain Topography, 1989, 1(2): 123–129.
Wong, P.K.H. Source modelling of the rolandic focus. Brain Topography, 1991, 4(2): 105–112.
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Waberski, T.D., Buchner, H., Lehnertz, K. et al. Properties of Advanced Headmodelling and Source Reconstruction for the Localization of Epileptiform Activity. Brain Topogr 10, 283–290 (1998). https://doi.org/10.1023/A:1022275024069
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DOI: https://doi.org/10.1023/A:1022275024069