[Quantitative analysis of capillary and neuron images under normal conditions and in dementia]

Stereological investigations (Leitz-Classimat) of the capillary net of young (19-44 yrs), old (85-95 yrs) and age-matched demented patients with Alzheimer's disease show a condensation (40%) of the capillary volume in the cerebral cortex of the Alzheimer group (n-3) compared with the age-matched controls (n-7), without change of the capillary diameter. These results represent gross atrophy of the frontal brain in senile dementia of Alzheimer type (SDAT). No changes of this kind can be observed between young individuals (n-6) and normal aged group. The behaviour of the capillary net in the putamen is different from that of the cortex. Already during normal aging a 80% condensation of the capillary volume is observed (capillary volume and length per unit increase, intercapillary distances decrease). A comparison between the aged group and the Alzheimer patients exhibits neither additional alterations of capillary parameters nor decreased volume of the putamen. In all anatomical layers of the frontal cortex a significant atrophy (27-36%) of neuronal perikarya (size and shape measurements with the TAS of Leitz) occurs in the Alzheimer group, compared with the normal aged ones. In the same way, neuronal surface area decreases by 30% in the putamen. Significant changes of perikaryal shape in both brain regions confirm marked neuronal atrophy in Alzheimer's disease. During normal aging only 85-95 years old group shows significantly smaller (15-35%) neurons in comparison to young individuals. Quantitative image analysis facilitates considerably evaluating new morphometrical data of the aging process in the human brain, which are important for a pharmacological concept of treating cerebral insufficiency symptoms.