P Anninos1, A Kotini, A Adamopoulos, N Tsagas. 1. Lab of Medical Physics, Medical School, Democritus University of Thrace, Alex/polis, Greece. anninos@med.duth.gr
Abstract
OBJECTIVE: The aim of this study is to investigate the influence of external magnetic stimulation (EMS) in epileptic patients using magnetoencephalographic (MEG) measurements and non-linear analytic techniques. METHODS: The examined group consisted of 15 men aged 19-56 years (mean: 39.5 +/- 11.3) and 15 women aged 15-53 years (mean: 36.7 +/- 11.4). For each one the magnetic activity was recorded from 32 points for each temporal lobe. External magnetic stimulation (EMS) with proper field characteristics (intensity: 1-7.5 pT, frequency: the alpha-rhythm of the patient (8-13 Hz)) was applied in the frontal, occipital and temporal lobes for 2 to 6 minutes and the emitted brain magnetic activity was recorded again. In order to investigate if there is any alteration in the MEG complexity underlying the neural dynamics characterizing the pathologic brain before and after the EMS, chaotic analysis approach was applied for the estimation of the dimensional analysis of the existing strange attractors. RESULTS: The application of EMS resulted in rapid attenuation of the MEG activity of epileptic patients. The obtained results of the dimensionality calculation provide a shift from lower to higher dimensional values. Such a shift is an indication that we are dealing with a chaotic system similar with the one characterizing normal subjects. CONCLUSIONS: The increased values of the dimensional complexity and the lower activity of the MEG after the application of EMS strongly supports the beneficial effects of EMS in epileptic patients.
OBJECTIVE: The aim of this study is to investigate the influence of external magnetic stimulation (EMS) in epilepticpatients using magnetoencephalographic (MEG) measurements and non-linear analytic techniques. METHODS: The examined group consisted of 15 men aged 19-56 years (mean: 39.5 +/- 11.3) and 15 women aged 15-53 years (mean: 36.7 +/- 11.4). For each one the magnetic activity was recorded from 32 points for each temporal lobe. External magnetic stimulation (EMS) with proper field characteristics (intensity: 1-7.5 pT, frequency: the alpha-rhythm of the patient (8-13 Hz)) was applied in the frontal, occipital and temporal lobes for 2 to 6 minutes and the emitted brain magnetic activity was recorded again. In order to investigate if there is any alteration in the MEG complexity underlying the neural dynamics characterizing the pathologic brain before and after the EMS, chaotic analysis approach was applied for the estimation of the dimensional analysis of the existing strange attractors. RESULTS: The application of EMS resulted in rapid attenuation of the MEG activity of epilepticpatients. The obtained results of the dimensionality calculation provide a shift from lower to higher dimensional values. Such a shift is an indication that we are dealing with a chaotic system similar with the one characterizing normal subjects. CONCLUSIONS: The increased values of the dimensional complexity and the lower activity of the MEG after the application of EMS strongly supports the beneficial effects of EMS in epilepticpatients.