Increasing loss of brain tissue with increasing dementia: a stereological study of post-mortem brains from elderly females.

Neocortical volumes, cortical thickness and volumes of archicortex, the ventricular system, the central grey matter and white matter were estimated using stereological methods on the brains from 28 elderly females (mean age 81.8 years) with increasing degree of senile dementia and brains from 13 (mean age 82.7 years) female controls who did not suffer from dementia. The estimator of pial surface area, as opposed to the other stereological techniques used in this study, was not strictly unbiased. Brains from patients with dementia (14 Alzheimer cases and 14 non-Alzheimer cases) had decreased cortex volume, and neocortical thickness was significantly reduced in the patients with dementia, with the highest degree of reduction in those whose dementia was most severe, as were the volumes of archicortex. No statistically significant difference was found in the volumes of cortex, white matter, central grey structures, ventricular volume or archicortex between the cases with Alzheimer's dementia (N = 14) compared with those with non-Alzheimer dementia (N = 14). The ventricular volume increased with increasing degree of dementia, but did not reach statistical significance in the dementia group compared with the control group. Surface area did not change in those patients with dementia, and no significant reductions were found in the volumes of white matter or central grey structures in the patients with dementia compared with controls.