Kaplan + Sadock's Synopsis of Psychiatry, 11e

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21.3 Dementia (Major Neurocognitive Disorder)

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C Figure 21.3-2

Photomicrographs of Alzheimer’s disease neuropathology. (A) Deposition of insoluble fibrillar A b into plaques begins in the neocortex, labeled here using an antibody against A b and appearing as reddish-brown deposits ( arrows ). (B) Bielchowsky stain of neocortex from an individual who died in advanced stages of Alzheimer’s disease (Braak stage VI). The A b plaques appear as dark brown in this preparation ( arrows ) and can be seen to be associated with dystrophic neuronal processes ( arrowheads ) in which insoluble microtubule-associate protein t (MAPT) aggregates appear as black deposits. This neurofibrillary pathology also appears extensively throughout the neuropil, and several neurofibrillary tangles can be seen ( open arrowheads ). (C) Bielchowsky stain of neocortex from an individual who died in a less advanced disease stage (Braak stage IV). Although some neurofibrillary tangles are still evident ( open arrowheads ), the degree of neurofibrillary pathology in the neuropil is substantially diminished. (D) Isolated neurofibrillary tangles ( open arrowheads ) in entorhinal cortex that can be seen in normal aging (Bielchowsky stain). Notice the lack of A b plaques and limited neuropil involvement. (All images obtained at 200 × magnification and provided courtesy of Dr. Ronald L. Hamilton, Department of Pathology, Division of Neuropathology, University of Pittsburgh School of Medicine.)