P4–384: Morphological alterations in Alzheimer's disease and their possible relationship to defective neurodevelopment

The correct positioning of neurons during neurodevelopment is the basis for proper brain function 1. Delicate control mechanisms modify the future brain's structure and physiology. Cortical development consists of cell proliferation, occurring within the 5th to the 20th week of pregnancy. There are few studies, so far, concerning the relationship between disruptions of neurodevelopment and Alzheimer' disease (AD). The aim of this study is to describe the structural and morphological alterations regarding neurodevelopment in a case series of AD This is a retrospective descriptive study of 4 cases -3 early-onset and 1 late-onset- of AD. The corresponding medical records and autopsy materials were examined. The tissues were formalin-fixed, paraffin-embedded, sectioned into 5–7 μm slices, and stained with H&E and silver techniques in order to perform photonic microscopy; and labeling for truncated tau (Tau7, C-terminal portion, fractions 3 and 423) and phosphorylated tau proteins (ALZ-50 231, 396, 404) to perform confocal microscopy. Macroscopically, all cases presented cerebral atrophy. The histopathological findings were neuritic plaques, neurofibrillary tangles, extensive failure of neuronal migration, cortical dysplasia, and hypoxic secondary changes. In white matter, there were heterotopias and demyelination.