Correlation of EEG, neuroimaging and histopathology in an epilepsy patientwith diffuse cortical dysplasia

The correlation between scalp EEG, intraoperative electrocorticogram, neuro imaging and histopathology was examined in an epileptic child with diffuse cortical dysplasia. The 6-year-old girl with moderate mental retardation ha d suffered from intractable complex partial and generalized epilepsies sinc e the age of 2 years. MR images demonstrated unilateral large macrogyria/po lymicrogyria and schizencephaly in the right occipital lobe. The epileptic focus was detected on the macrogyria by EEG and single photon emission tomo graphy. However, the intraoperative electrocorticogram showed frequent spik es from the polymicrogyria and no paroxysmal activity in the macrogyria. Th e polymicrogyria and the macrogyric lesion were resected, using an image-gu ided system. The histological findings revealed that the macrogyria was cov ered with and separated by glial bundles. It has been reported that epilept ogenicity is produced from abnormal neurons and their arrangement in cortic al dysplasia; in this case, however, the major dysplastic lesion had no epi leptogenicity; rather the focus might be in the polymicrogyria around the l esion.