Effects of Magnetic Fields on EEG-Recorded Brain Wave Activity


Follow this link to read some abstracts of publications from this project.

Clinical studies of the effects of magnetic fields of relatively weak flux density (up to 4 mT) on the brain wave activity of epileptic patients are being undertaken as part of a co-operative project with the Swiss Federal Institute of Technology (ETH-Zurich), the University Hospital - Zurich. The patients, usually suffering from Mesial Temporal Lobe Epilepsy (MTLE), cannot be treated with available medication and are being evaluated for possible surgical correction of the disease. In order to operate, however, the epileptogenic focus must be located.

To accomplish this, electrical activity in the brain is evaluated with electroencephalography (EEG) recordings from surgically-implanted electrodes. The data from the implanted electrodes give a clearer indication of the location of the epileptogenic focus as well as the type of epilepsy involved. This type of evaluation, however, can take up to a few weeks, during which time the patient must be monitored constantly and the electrodes left implanted. One of the goals of this project is to use magnetic fields to evoke typical seizure patterns in these patients in order to reduce the amount of time taken to locate the focus of epileptic activity. In addition, it is hoped that this study will result in a clearer understanding of how the human central nervous system interacts with magnetic fields.

Results thus far indicate that it may be possible to evoke epileptiform discharges in these patients with the application of DC magnetic fields. (1,2,3,4). The change in field appears to be more important that the application of static fields over a longer period of time. In addition, in all patients analyzed, EEG spectral content is altered on the side affected by the epilepsy with respect to control periods.

REFERENCES:

[1] Dobson, JP, M Fuller, HG Wieser, and S Moser (1993) Evocation of epileptiform activity by weak DC magnetic fields. American Geophysical Union Meeting, Baltimore, Maryland. EOS, v. 74, no. 16.

[2] Dobson, JP, M Fuller, S Moser, HG Wieser, JR Dunn and J Zoeger (1995) Evocation of epileptiform activity by weak D.C. magnetic fields and iron biomineralization in the human brain. In: Biomagnetism: Fundamental Research and Applications, eds. C Baumgartner, L Deecke, G Stroink, SJ Williamson. Elsevier, Amsterdam: 16-19.

[3] Fuller, MD, JP Dobson, HG Wieser and S Moser (1995) On the sensitivity of the human brain to magnetic fields: Evocation of epileptiform activity. Brain Res.Bull., 36: 155-159.

[4] Dobson, J, M Fuller, S Moser, HG Wieser (1997) Changes in Paroxysmal Brainwave Patterns of Epileptics by Application of DC Magnetic Fields. In Preparation.

COLLABORATORS:

Prof. H.G. Wieser (University Hospital-Zurich), Prof. Niels Kuster (ETH-Zurich), Paola Grassi (ETH-Zurich), Prof. M.D. Fuller (Univ. of Hawaii), Prof. Charles Wilson (U.C.L.A. Medical Center - Los Angeles).


Contact Information

For more information on this research, e-mail Jon Dobson (jdobson@cyllene.uwa.edu.au)
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