An elderly patient dies with chronic dementia. At autopsy, the brain showed diffuse coical atrophy with relative sparing of primary motor and sensory areas. Which of the following would most likely be a prominent feature on microscopic examination of her brain tissue?

The clinical history and gross pathology suggest Alzheimer's disease. Neurofibrillary tangles and senile plaques are found primarily in higher order association coex. Other microscopic features of Alzheimer's disease include granulovacuolar degeneration and, sometimes, Hirano bodies. Central chromatolysis is a loss of histological staining seen in lower motor neurons whose axons have been damaged, for example by injury to the ventral roots. Gliosis of the caudate nucleus is a feature of Huntington's disease, and ceain other degenerative diseases of the basal ganglia. Lewy bodies (eosinophilic intracytoplasmic spherules) and loss of pigmented neurons in the substantia nigra are features of Parkinson's disease. Ref: Kwentus J.A., Kirshner H.S. (2008). Chapter 14. Delirium, Dementia, and Amnestic Syndromes. In M.H. Ebe, P.T. Loosen, B. Nurcombe, J.F. Leckman (Eds), CURRENT Diagnosis & Treatment: Psychiatry, 2e.