Table of Contents
Washington University Experience | NEURODEGENERATION | Alzheimer Disease | Gross Pathology | 4B Case 4 Denouement
Neuro Microscopic Summary: ---- Multiple sections of frontal, parietal, temporal and occipital neocortices show numerous senile plaques and neurofibrillary tangles along with regional to focal loss of neurons. The plaques are also highlighted by beta-amyloid (including microvasculature) and as neuritic plaques by phosphorylated tau (PHF). The hippocampus also shows evidence of granulovacuolar degeneration and numerous Hirano bodies. Superficial microvacuolar cortical pathology involves the neocortices but an alpha-synuclein stain is negative. ---- Neuro Diagnosis Comment: Histopathologically various changes including neuronal loss, neuronal tangles (highlighted by the accumulation of Tau proteins), diffuse and “neuritic” plaques containing Beta amyloid, as well as vascular deposition of Beta-amyloid are typically seen beginning in the limbic system and eventually involving the neocortex and rarely the cerebellum. The constellation of neuropathologic findings in this case as well as their frequency and distribution in a patient with dementia are diagnostic of Alzheimer disease, meeting the Khachaturian, CERAD, NIA/Reagan and 2011 NIA-AA guidelines for assessment of Alzheimer neuropathological change, the latter with a score of A1B3C2 (intermediate change). The occipital lobe sections show large numbers of senile plaques and neurofibrillary tangles and appear to represent a more exaggerated involvement by Alzheimer disease, sometimes called posterior cortical atrophy, although this patient did not show visuospatial and visuoperceptual deficits. Often additional pathologies contributing to dementia as well as movement disorders may be seen including diffuse Lewy body disease (highlighted by antibodies to alpha-synuclein), Pick's disease, corticobasal degeneration and frontotemporal dementia (most often recognized by staining with anti-TDP-43). In this case characteristic features of these diseases were not noted by morphological or immunohistochemical examination.
