Tomasz Zyss

Simulation of magnetic stimulation of the brain

The paper presents a computer simulation of the transcranial magnetic stimulation of the brain with a low-frequency magnetic field, a technique which is proposed to replace the electroconvulsive treatment in psychiatry. The field model is based on the T-/spl Omega/ formulation, that, by the low electric conductivity and constant magnetic permeability of the human tissue, allows us to build a finite-element model of the head only.

Therapeutic efficacy assessment of weak variable magnetic fields with low value of induction in patients with drug-resistant depression.

BACKGROUND The aim of this prospective study was to verify whether magnetostimulation with weak variable magnetic fields with low value of induction could enhance the effects of pharmacological therapy in drug-resistant depression. MATERIALS AND METHODS Thirty patients, 26 women and 4 men, with drug-resistant depression were enrolled in the study. The subjects from Group No. I (14 patients) were given fluvoxamine and treated with weak variable magnetic field using the VIOFOR JPS device; the subjects from Group No. II (16 patients) were also given fluvoxamine but they were treated with the VIOFOR JPS device in placebo mode. Changes in depressive symptoms were estimated with the 21-point Hamilton Depression Scale (HDRS), Montgomery-Asberg Depression Scale (MADRS) and Beck Depression Inventory (BDI) questionnaire. RESULTS After 15 days of treatment highly significant differences were revealed between the patients treated with magnetic field and the patients treated with placebo: the final HDRS score was 53% of the initial value for the group receiving combined treatment, and 86% in the placebo group (p<0.001); for MADRS score the values were 51% and 88% (p<0.001), respectively, and for BDI 60% and 87% (p<0.001). Thus, the average effect of placebo applied with fluvoxamine was a ca. 15% reduction of symptoms, while the concurrent application of magnetic field and SSRI treatment resulted in a 40-50% improvement. CONCLUSION Our study indicates that adding a two-week low-induction variable magnetic field stimulation to a classical pharmacologic therapy reduces the intensity of symptoms in patients with drug-resistant depressive disorders.

Modelling of eddy currents induced in human brain by transcranial magnetic stimulation

Deals with the problems of interactions between the electromagnetic field and the human brain. In particular, the problem of eddy currents in brain tissue induced for medical purposes is discussed. The mathematical modelling of the phenomenon is presented.