Histopathological examinations revealed evidence of hippocampal sclerosis
Haematoxylin-Eosin staining of the hippocampal sections obtained from patients with MTLE-HS revealed typical sclerotic hippocampus consists of massive cell loss, cystic cavities, neuronal degeneration, gliosis and infiltration of inflammatory cells (Figure 1a). The NeuN immunohistochemistry confirms pyramidal neuron loss, presence of ischemic neurons and abnormal neuronal architecture (Figure 1b). Another hallmark of the hippocampal sclerosis is reactive astrogliosis with hypertrophic astrocytes manifesting distinctive GFAP staining and thick, long projections (Figure 1c). In autopsy control tissue sections, negligible neuronal loss was observed (Figure 1d and e). The GFAP immunohistochemistry did not reveal any reactive astrogliosis (Figure 1f). These data suggested that architectural alterations like, pyramidal cell apoptosis, necrosis and reactive astrogliosis were observed in the hippocampal samples of the MTLE-HS patients.