A morphologic study of central nervous system aging in Hiroshima, Japan.

The presence of intraparenchymal small vessel arteriosclerosis, senile plaques, neurofibrillary tangles and granulovacuolar degeneration was quantified in the brains of autopsided patients from three age groups: 1) 90--99 years old 2) 70--79 years old and 3) 50--59 years old. Neurofibrillary tangles particularly in the hippocampus were the best indicator of chronologic aging, but senile plaques and granulovacuolar degeneration were also age related. Intraparenchymal small vessel sclerosis, cerebral infarction and hemorrhage, cause of death and radiation exposure at the time of the atomic bomb explosion in Hiroshima apparently had little or no effect on the development of these aging changes. Each type of aging change appeared to be independent of the others, to progress to a different combination of physiologic processes.