Magnetoencephalographic studies of two cases of diffuse subcortical laminar heterotopia or so-called double cortex

Two cases (a young male and a girl, suffering intractable epilepsy) of diffuse subcortical laminar heterotopia, or so-called double cortex (DC) have been investigated using magnetoencephalography (MEG). MEG confirmed involvement of both cortices (hetero- and normocortex) in the genesis of interictal spikes, and, according to the heterogeneity of DC syndrome, some differences were observed: spike initiation in the normocortex and latter involvement of the heterotopic cortex in the man, and rather a cancellation in both cortices in the girl. In addition, participation of heterotopic cortex in physiological activities could be demonstrated in the man.