Does magnetism affect human behavior

Preparation of a measurement experiment in the EEG laboratory of the Neurological University Clinic. The Helmholtz coil built by the ETH is "placed" over the head of an epilepsy patient and the patient's EEG is measured using intracranial electrodes that are taken directly from the epilepsy focus.

The investigation of the influence of weak magnetic fields on the human electroencephalogram benefits from the interdisciplinary collaboration between the Neurological Clinic, Department of Epileptology and EEG at the University Hospital Zurich, the Institute for Maximum Frequency and the Institute for Geophysics at ETH Zurich. The aim of this project is to research the effects of weak magnetic fields on the human brain.

Specifically, the possibility is being investigated whether and how one can specifically trigger epilepsy attacks in patients with severe epilepsy. This goal, which is absurd at first glance, makes sense and is worth striving for on closer inspection.

There are people with epilepsy who cannot be helped with anti-epileptic medication. In such cases, the possibility of surgical epilepsy treatment should be considered. The area of ​​the brain that caused the seizures is surgically removed after detailed investigations. The "epilepsy focus" is often found in the temporal lobe, more precisely in the hippocampus on one side.

The patient must be hospitalized for the relevant preliminary clarifications. Direct recordings from the brain are often necessary, that is, in a small operation, EEG recording electrodes are brought to the corresponding part of the brain through openings in the skull. After this operation, the "deep EEG" and the clinical behavior of the patient are constantly monitored and recorded using complex technology (telemetric long-term recordings) until at least two epileptic seizures can be recorded, which are necessary to characterize the epilepsy focus.

The time between the implantation of the electrodes and the successful recording of two epileptic seizures can be up to two weeks (in extreme cases even longer). This is stressful and costly for the patient. There is therefore a desire to shorten this period of time in order, on the one hand, to shorten the patient's suffering and, on the other hand, to reduce costs.

This is exactly where the project comes in: Previous studies have shown that there are magnetic minerals in the human brain. Using a specially developed coil (Helmholtz coil, 4 mTesla, homogeneous field), a weak magnetic field is built up around the patient (100 times stronger than the earth's magnetic field, around 400 times weaker than MRI). Its effects on the patient's brain waves are measured in sophisticated experiments. Our results obtained so far show that weak magnetic fields significantly influence the brain waves of the patients.

Using these measurements and the analysis of tissue samples taken during epilepsy operations, we try to create models to better understand the effects of magnetic fields on the human brain. Of particular interest is the question of whether and how magnetic fields can be used as diagnostic tools to improve the localization of the epilepsy focus. Another important, but currently unresolved question is whether and to what extent the results found in people suffering from seizures are also valid in healthy people. The results of this research project are therefore also of great interest in the context of the “electrosmog discussion”, which is being followed very closely by the public. Heinz-Gregor Wieser,

Paola P. Schultheiss-Grassi

The team: Professor H. G. Wieser, Department of Neurology, Department of Epileptology and EEG, University Hospital Zurich; Professor N. Kuster, Institute for Maximum Frequency ETHZ; Professor W. Lowrie, Professor F. Heller, Dr. J. Dobson and P. P. Schultheiss-Grassi, Institute for Geophysics ETHZ.

Universitypress service - Press office of the University of Zurich
Nicolas Jene ([email protected])
Last update: 01/09/98