Caracterização dos subtipos histopatológicos de esclerose hipocampal e sua relação com os dados clínicos, neuropsicológicos e imaginológicos

• Ano de defesa: 2016
• Autor(a) principal: Jardim, Anaclara Prada [UNIFESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Temporal lobe epilepsy; Hippocampus; Neuropathology; Sclerosis; Epilepsia do lobo temporal; Hipocampo/patologia; Neuropatologia; Esclerose/patologia
• Link de acesso: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=4318561; http://repositorio.unifesp.br/handle/11600/47931

Hippocampal sclerosis (HS) is the commonest histopathological finding in mesial temporal lobe epilepsy and neuropathological subtypes of HS are defined by the qualitative patterns of neuronal loss as assessed on NeuN immunohistochemistry. HS, however, may appear intermediate (Ind-HS) or difficult to classify. HS subtypes have been reported to predict memory deficits and seizure outcome following surgery. The purpose of this study was to verify if quantitative analysis using dendritic marker MAP2 would provide a more stringent classification of HS. Furthermore, analyse if HS subtypes, as well as alteration of hippocampal axonal networks, regenerative capacity and neurodegeneration correlated with MRI hippocampal volumes, accompanying memory deficits, and post-operative seizure outcome. This study was performed in two different centres in Brazil and England. The total number of patients selected was 154 (101 type 1 HS, 23 type 2, 2 type 3, 11 no-HS and 18 Ind-HS). Quantitative analysis was carried out on NeuN and MAP2 and a labelling index (LI) calculated for hippocampal subfields. Markers for hippocampal regenerative activity (MCM2, nestin, olig2, calbindin), degeneration (AT8/phosphorylated TAU), mossy-fibre pathway re-organization (ZnT3), and presence of basal dendrites on granule cells were also evaluated. Pathology measures were correlated with clinical, imaging, memory test scores, and post-operative outcomes, at one year following surgery. The mean MAP2 LI in CA4 in Ind-HS was statistically aligned with type 2 HS but not with NeuN labelling. Moderate and severe memory deficits were noted in all HS types. Memory deficits were correlated with multiple pathology factors including lower NeuN or MAP2 LI in CA4, CA1, dentate gyrus and subiculum, poor preservation of the mossy fibre pathway and fewer basal dendrites on granule cells. Smaller hippocampal volumes were associated with type 1 and 2 HS and with CA1, CA3, and CA4 neuronal density. Type 1 HS patients had better seizure control following surgery. Decline in memory at one year associated with AT8 labelling in the subiculum and dentate gyrus and the density of nestin-labelled cells in CA4, but not with HS subtype. We conclude that MAP2 is a useful adjunct in the classification of HS. The smaller hippocampal volumes on MRI indicate significant neuronal loss and HS pattern. HS subtype classification alone is not predictive of memory function, which was associated with multiple pathology factors including hippocampal axonal pathways, regenerative capacity and degenerative changes.