Aging of the human cerebellum: a stereological study.

Cerebella from 19 normal Caucasian males, ages 19-84 years, were studied using stereological methods. Cerebellum was divided into four different regions: the anterior and posterior lobe, the vermis, and the flocculonodular lobe. Total volume of the cerebellar cortex and white matter, cerebellar surface area, total Purkinje and granule cell number, and the distribution of the volumes of the Purkinje cells and their nuclei were estimated in all four regions. The global white matter was reduced by 26% with age; the mean volume of the Purkinje cell body was decreased by 33% with no decrease in the volume of the Purkinje cell nuclei. A tendency towards a 16% total cerebellar volume loss was seen without a concomitant neuron loss. No global Purkinje or granule cell loss was detected with age, total Purkinje cell number being 28 x 10(6) (coefficient of variation, CV = 0.16) and total granule cell number 109 x 10(9) (CV = 0.17). However, a significant change was observed with age in the anterior lobe, where a selective 40% loss of both Purkinje and granule cells was found. Furthermore, a 30% loss of volume, mostly due to a cortical volume loss, was recorded in the anterior lobe, which is predominantly involved in motor control.