A 70 year old male patient dies with severe dementia. Autopsy demonstrates marked atrophy of the frontal and temporal lobes, with relative sparing of the rest of the brain. Which of the following microscopic features would be most useful in establishing the diagnosis?

Selective frontal and temporal atrophy in a demented patient suggests Pick's disease. Microscopically, severe neuronal loss and astrocytosis are seen. The characteristic microscopic finding in this disorder is the presence of Pick's bodies, which are intracytoplasmic spherules composed of paired helical filaments, seen best with silver stains. 1st choice describes senile plaques. These are seen in Alzheimer disease as well as in some normal elderly individuals. 2nd choice describes Lewy bodies, seen in Parkinson's disease. 4th choice describes the inclusion bodies typically seen in glial cells and endothelial cells in cytomegalovirus encephalopathy. Ref: Ropper A.H., Samuels M.A. (2009). Chapter 39. Degenerative Diseases of the Nervous System. In A.H. Ropper, M.A. Samuels (Eds), Adams and Victor's Principles of Neurology, 9e.