Age-related change in volumes of the ventricles, cisternae, and sulci: a quantitative study using computed tomography.

Using computed tomography, the authors studied enlargement of the ventricles and the free spaces (cisternae and sulci) above the level of the tentorium cerebelli during aging in 97 men and 55 women with no neurologic disturbances, ranging in age from 17 to 86 years, and calculated a ventricular volume index (100% X ventricular volume/cranial cavity volume) and a free space volume index (100% X free space volume/cranial cavity volume). Both the ventricular volume and the ventricular volume index started to increase significantly in the forties in men and in the fifties in women. Both the free space volume and the free space volume index were found not to increase until the sixties in both men and women. Both the ventricular volume index and the free space volume index were smaller in hypertensives than in normotensives in men over age 65.