Brain Topography

, Volume 8, Issue 3, pp 215–221 | Cite as

Sources of spontaneous slow waves associated with brain lesions, localized by using the MEG

  • Juergen B. Vieth
  • Helmut Kober
  • Peter Grummich
Invited Papers

Summary

Electric or magnetic slow wave brain activity can be associated with brain lesions. For an accurate source localization we transformed the magnetoencephalographic (MEG) coordinate system to the magnetic resonance imaging (MRI) system by using a surface fit of the digitally measured head surface and the reconstructed surface of the MRI scan. Furthermore we solved the problem to separate sources of focal activity from other multiple sources by introducing a spatial average, the Dipole Density Plot (DDP). The DDP shows in a quantified manner concentrations of dipoles across time. The DDP uses the single dipole model adequately, because only those signal sections will be analyzed, where one component contributes to the signal predominantly. In all cases, where multiple sources concurrently active are to be localized, a current distribution analysis will be used, the Current Localization by Spatial Filtering (CLSF). All source localization procedures were tested using structural brain lesions, which were verified by imaging techniques (MRI or CT), showing the results in close topographical relation to the lesions. The results so far let us assume, that the DDP and the CLSF are valuable tools to localize sources of focal spontaneous slow wave electrical brain activity.

Key words

Slow MEG waves Brain lesions Validation Multisource activity Dipole-Density-Plot (DDP) Current localization by spatial filtering (CLSF) 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Abraham-Fuchs, K., Lindner, L., Wegener, P., Nestel, F. and Schneider, S. Fusion of Biomagnetism with MRI or CT images by contour-fitting. Biomed. Engineer. (Berlin), 1991, 36 (Suppl. 1): 88–89.Google Scholar
  2. Gallen, C., Schwartz, B., Pantev, C., Hampson, S., Sobel, D., Hirschkoff, E., Rieke, K, Otis, S. and Bloom, F. Detection and localization of delta frequency activity in human strokes. In: Hoke, M., Erne, S.N., Okada, Y.C. and Romani, G.L. (Eds.), Biomagnetism, Clinical Aspects. Exerpta Medica, Amsterdam, London, New York, Tokyo, 1992: 301–305.Google Scholar
  3. Grummich, P., Vieth, J. and Kober, H. Magnetic fields of the brain analyzed by a multiple dipole approach using factor analysis. Clinical Physics Physiol. Meas., 1991, 12 (Suppl. A): 61–66.Google Scholar
  4. Grummich, P., Vieth, J., Kober, H. and Schok, T. Separation of sources of alpha activity in multichannel MEG. In: Hoke, M., Erne, S.N., Okada, Y.C. and Romani, G.L. (Eds.), Biomagnetism, Clinical Aspects. Exerpta Medica, Amsterdam, London, New York, Tokyo, 1992: 39–42.Google Scholar
  5. Hämäläinen, M. Anatomical correlates for magnetoencephalography: integration with magnetic resonance images. Clin. Phys. Physiol. Meas., 1991, 12 (Suppl. A): 29–32.Google Scholar
  6. Iramina, K. and Ueno, S. Spatial properties of magnetic fields produced by radially oriented dipoles in inhomogenous sphere. In: Atsumi, K., Kotani, M., Ueno, S., Katila T. and Williamson, S.J. Biomagnetism '87. Tokyo Denki University Press, Tokyo, 1988: 106–109.Google Scholar
  7. Jung, R. Neurophysiologische Untersuchungsmethoden. II. Das Elektroencephalogramm (EEG). In: Handbuch der Inneren Medizin, 4th edition, Springer, Berlin, 1953: 1- 181.Google Scholar
  8. Kober, H., Grummich, P. and Vieth, J. Fit of the digitized head surface with the surface, reconstructed from MRI-Tomography. In: Baumgartner, C., Deeke, L., Stroink, G., Williamson, S.J. (Eds.), Biomagnetism: Fundamental Research and Clinical Applications. Elsvier Science, IOS Press, Amsterdam, Oxford U.K., Burke VA USA, Tokyo, 1995: 309–312.Google Scholar
  9. Kober, H., Vieth, J., Grummich, P., Daun, A., Weise, E. and Pongratz, H. The factor analysis used to improve the dipole-density-plot (DDP) to localize focal concentrations of spontaneous magnetic brain activity. Biomed. Engineer. (Berlin), 1992, 37 (Suppl. 2): 164–165.Google Scholar
  10. Mergenhagen, D., Creutzfeldt, O. and Neuweiler, G. Beziehungen zwischen Aktivitat kortikaler Neurone und EEG- Wellen im motorischen Kortex der Katze bei Hypoglykämie. Arch. Psychiat. Zeitschr. ges. Neurol., 1968, 211: 43–62.Google Scholar
  11. Nagata, K, Mizukami, M., Araki, G., Kawase, T. and Hirano, M. Topographic electroencephalographic study of cerebral infarction using computed mapping of the EEG (CME). J. Cereb. Blood Flow Metab., 1982, 2: 79–88.Google Scholar
  12. Nagata, K., Yunoh, K., Araki, G. and Mizukami, M. Topographic electroencephalographic study of transient ischemic attacks. Electroenceph. clin. Neurophysiol., 1984, 58: 291–301.Google Scholar
  13. Nagata, K., Gross, C.E., Kindt, G. W., Geyer, J.M. and Adey, G.R. Topographic electroencephalographic study with power ratio index mapping in patients with malignant brain tumors. Neurosurgery, 1985, 17: 613–619.Google Scholar
  14. Nagata, K., Tagawa, K., Hiroi, S., Nara, M., Shishido, F. and Uemura, K. Quantitative EEG and positron emission tomography in brain ischemia. In: G. Pfurtscheller and F.H. Lopes da Silva (Eds.), Functional Brain Imaging, Hans Huber Publishers, Toronto, Lewiston N.Y., Bern, Stuttgart, 1988: 239–250.Google Scholar
  15. Obrist, W.D., Sokolof, L., Lassen, N.A., Lane, M.H., Butler, R.N. and Feinberg, I. Relation of EEG to cerebral blood flow and metabolism in old age. Electroenceph. clin. Neurophysiol., 1963, 15: 610–619.Google Scholar
  16. Robinson, S.E., and Rose D.F. Current source image estimation by spatially filtered MEG. In:M. Hoke, S.N. Erne, Y.C. Okada, G.L. Romani (Eds.), Biomagnetism, Clinical Aspects, Exerpta Medica, Amsterdam, London, New York, Tokyo, 1992: 761–765.Google Scholar
  17. Sato, S. The localization of epileptiform activity: The NIH experience. In: Bachmann, K., Stefan, H., and Vieth, J. (Eds.), Biomagnetism: Principles, Models and Clinical Research. Palm and Enke, Erlangen, 1992: 44–47.Google Scholar
  18. Stefan, H., Schueler, P., Abraham-Fuchs, K. and Schneider, S. Ictal and interictal multichannel magnetic field recordings of epileptiform activity: Quantitative description of centers of focal epileptic activity. In Hoke, M., Erne, S.N., Okada, Y.C. and Romani, G.L. (Eds.), Biomagnetism, Clinical Aspects, Exerpta Medica, Amsterdam, London, New York, Tokyo, 1992: 87–91.Google Scholar
  19. Toole, J.F. Transient ischémic attacks. In: Toole, J.F. (Ed.), Cerebrovascular Disorders, Raven Press, New York, 1984: 101–116.Google Scholar
  20. Vieth, J. Magnetoencephalography in the study of stroke (cerebrovascular accidents). In: Sato, S. (Ed.), Advances in Neurology, Vol 54: Magnetoencephalography. Raven Press, New York, 1990: 261–269.Google Scholar
  21. Vieth, J. Comparison of single-channel and multi-channel MEG recordings. In: Maurer, K. (Ed.), Imaging of the Brain in Psychiatry and Related Fields. Springer, Berlin, Heidelberg, New York, 1993: 202–212.Google Scholar
  22. Vieth, J., Grummich, P., Sack, P., Kober, H., Schneider, S., Abraham-Fuchs, K., Kerber, U., Ganslandt, O. and Schmidt, T. Three dimensional localization of the pathological area in cerebrovascular accidents with multichannel magnetoencephalography. Biomed. Engineer. (Berlin), 1990, 35 (Suppl. 2): 238–239.Google Scholar
  23. Vieth, J., Kober, H., Weise, E., Daun, A., Moeger, A., Friedrich, S. and Pongratz, H. Functional 3-D localization of cere- brovascular accidents by magnetoencephalography (MEG). Neurol. Res. 1992a, 14 (Suppl.): 132–134.Google Scholar
  24. Vieth, J., Kober, H., Sack, G., Grummich, P., Friedrich, S., Moeger, A., Weise, E., Daun, A. and Pongratz, H. The efficacy of the discrete and the quantified continous dipole density plot (DDP) in multichannel MEG. In: M. Hoke, M., Erne, S.N., Okada, Y.C. and Romani, G.L. (Eds.), Biomagnetism, Clinical Aspects, Exerpta Medica, Amsterdam, London, New York, Tokyo, 1992b: 321–325.Google Scholar
  25. Vieth, J., Kober, H., Weise, E., Grummich, P., Pongratz, H., Fenwick, P.B.C. and Claus, D. Magnetic interictal epileptic brain activity localized by using the single and the two dipole model. Biomed. Engineer.(Berlin), 1992, 37 (Suppl. 2): 162–163.Google Scholar
  26. Vieth, J., Sack, G., Kober, H., Grummich, P., Friedrich, S., Moeger, A., Weise, E. and Pongratz, H.Magnetoencephalography, a method to localize silent transient ischémic attacks (TIA) using an improved dipole-density-plot. Biomed. Engineer.(Berlin), 1991, 36 (Suppl. 1): 155–156.Google Scholar
  27. Walter, W.G. The localization of cerebral tumors by electroencephalography. Lancet, 1936, 2: 305.Google Scholar

Copyright information

© Human Sciences Press, Inc 1996

Authors and Affiliations

  • Juergen B. Vieth
    • 1
  • Helmut Kober
    • 1
  • Peter Grummich
    • 1
  1. 1.Dept. of experimental NeuropsychiatryUniversity of Erlangen-NürnbergErlangenGermany

Personalised recommendations