Effects of Volume Current on Localization of Focal Epileptic Activity
In the localization of focal epileptic activity, there are some cases that the estimated positions scatter. In these cases, the improvement on the localization of focal epileptic activity is expected. Usually the foci of epilepsy are localized with the spherical model assuming a single current dipole for a focus from MEG (Magnetoencephalogram). However, skull and palate are in a head, then a head is not spherical and is inhomogenous. We previously investigated the effects of volume current on the source localization by experiments and computer simulation with a single-layer hemispherical phantom. From the results, it was found that the contribution of volume current to the MEG increases when the current dipole exists on the region near the bottom and in the deep place of the head . In this paper, we investigate the possibility of improvement on the localization of focal epileptic activity with the MEGs of three subjects of focal epilepsy by considering the effects of the volume current.
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