Abstracts

Rationale: We aimed to characterize the histopathological changes in the temporal cortex and hippocampus in 84 cases of refractory temporal epilepsy. Methods: All patients were studied according to standardized presurgical protocol and submitted to temporal lobectomy and hippocampectomy. For the histopathological diagnosis of neuronal migration disorder (NMD) immunohistochemical stains for GFAP, nestin and vimentin were performed. Bielschowsky silver and cupric amino stains were routinely performed. Results: Histopathological findings observed in the temporal cortex were diffuse architectural disorganization, atypical dendritic processes that resemble the dysmorphic neurons of cortical dysplasias, neuronal cytomegaly, ballon cells (in several specimens) with abundant eosinophillic cytoplasm, nodular heterotopias, microdysgenesis, loss of normal laminar architecture with gliosis involving cortical layers, inflammation and reactive astrocytosis. The specimens with dysmorphic cells also contained other cytoarchitectural abnormalities including bilamination of the cortical layer in three cases; and giant cells with abnormal orientation, loss or dispersion of granular cells of the dentate gyrus, with hyperchromatic, disorganization and dysplastic pyramidal cells of CA1 in two cases. Dual pathology (both AHS and NMD) was observed in 36.9% of cases and showed relatively equal distributions of NMD using Palminis Classification IA, IB, IIA, IIB. Conclusions: Our observations suggest that there is a strong association between NMD and AHS and this coexistence might be responsible for temporal lobe epilepsy. Study supported By CONACYT, México (Grants 53061/67676-M)