Meg Evaluation of Epileptic Activity in the Time and Frequency Domain

Abstract

We investigated the localization of current sources in the time and frequency domain from spontaneous MEG data recorded from nine epileptic patients (six females; three males) randomly selected, who had a mean age of 41 years old (range of 17-78 years old), with different types of epilepsy. The MEG data were recorded in a magnetically shielded room with a whole-head 122 channel biomagnetometer. For each MEG spike, we calculated the single Equivalent Current Dipole (ECD) sources at the initial spike peaks with a spherical model. MRI and EEG findings were available in patients' records. Prominent low frequencies can be seen in the majority of channels. For each patient there was an increase of the frequency range after the ECD in comparison with the frequency range before the ECD, in the whole study group due to epileptic discharge which is statistically significant (p=0.02). There was also a statistical significant difference in the increase of the frequency range in four patients with pathologic MRI (p=0.05), in five patients with normal MRI (p=0.02), in five patients with a high incidence of seizures (p=0.04) and in four patients with onset<10 years (p=0.04). The MEG analysis of neuromagnetic data gives information about the modification of the frequency range in the epileptic brains.

The Use of Magnetoencephalography to Evaluate Febrile Seizures and Epilepsy in Children

“…Informed consent for the methodology and the aim of the study was obtained from their parents prior to the procedure. The MEG recordings were carried out in a magnetically shielded room with a whole head 122-channel-biomagnetometer (Neuromag-122, Helsinki, Finland) (Anninos et al, 2010;Kotini et al, 2010;2008;2004;2002;Tonoike et al, 1998;Antoniou et al, 2004) (Figure 1). All studies performed precisely 10 days after fever subsided for the purpose of comparison.…”

Frequency Analysis for The Effect of Pico Tesla-Transcranial Magnetic Stimulation in Epilepsy Patients Using Magnetoencephalography

“…It is designed to create pT-TMS range modulations of magnetic flux in the alpha frequency range (8-13Hz) of every patient. The pT-TMS device was configured for each individual to produce a square wave (so as to resemble the firing activity of neurons in the brain) [7][8][9][10][11][12] .…”