SYSTEMATIC histologic studies by means of silver-staining techniques of large numbers of brains from autopsies at St. Elizabeths Hospital have demonstrated the widespread distribution of argyrophilic plaques and neurofibrillary changes in a proportion of persons larger than had been anticipated. The brains of such patients were in general smaller than the average and showed varying degrees of atrophy and mild or advanced ventricular dilatation without obstruction to the flow of cerebrospinal fluid. Sclerotic or atheromatous plaques were often observed in the walls of large vessels, but the vascular changes did not appear to be of sufficient magnitude to account for the clinical picture. Only in rare instances were focal lesions observed in this group.
Many of the patients were above the age limits to which Alzheimer's disease is generally attributed. A large number had entered the hospital at an advanced stage of their illness, when neurologic signs were prominent. The