Abstracts

Rationale: Approximately 30% of patients with epilepsy develop intractable seizures [i.e., seizures persist despite accurate diagnosis and carefully monitored treatment with antiepileptic drugs (AEDs. The mechanisms underlying multidrug resistance (MDR) in epilepsy are still elusive. Some risk factors have been identified in patients, (i.e., time of onset of epilepsy, type and etiology of seizures, and number of seizures before the start of the treatment), the form of chronic progressive epilepsia partialis continua (EPC) of childhood is diagnosed how Rasmussen s encephalitis upon histologic confirmation. It remains a rare and not easily diagnosed syndrome for which no etiology has been ascribed. The purpose of this study was to examine the structural alterations in BBB and the immunological and cellular characteristics in the brain obtained after hemispherectomy in patient with EPC, as well as to know the Mdr-1 expression in the same tissue. Methods: Fourteen cases were analyzed from epileptic tissue from cerebral cortex, obtained from patients with Rasmussen s encephalitis . The tissue were processing to be including in paraffin y a block serial of each section was frozen and cut at criostate to -20 C. All blocks of tissue (paraffin and frozen) were cut and 12 um. Other tissue block was used to immunofluorescence stain in criostat sections to -20 C, for electron-microscopic study the tissues were fixed in Karnovski solution and one samples were collected in vial free of RNAasas and rapidly frozen at N2 liquid to identify Mdr-1 by Western blot technique. Results: The results showed damage in the blood brain barrier that coexisted with an increase in the expression of the Mdr-1 in vascular endothelia, astrocites and neurons close the vessel mainly microvessel in the epileptic focus in gray matter and less in the white matter and several grade of inflammatory process.Conclusions: The results indicate that the degenerative process in this type of patient has an evolutionary course with the advance of the tissue damage, in addition are associated with alterations in the elements of the BBB and an increase in the expression of protein the transporting Mrp- drug that probably contributes to make but these patients refractory. This study was supported by the National institute of Science and Technology GDF(IPFTU-08-27), National Council for Sciences and Technology of Mexico (grants S52955-M)