MAPT and Alzheimer disease: Microscopic examination revealed severe Alzheimer’s disease neuropathologic change, A3B3C3 according to NIA-AA guidelines.19 Abundant neurofibrillary tangles, neuropil threads and neuritic plaques were seen in the frontal, temporal and occipital cortices and hippocampus, with many neurofibrillary tangles in the hippocampal pyramidal cell layer, on immunohistochemistry for hyperphosphorylated tau (AT8), consistent with Braak and Braak stage VI (Fig. 6A).