Studies on Cerebral Circulation and Metabolism in Hypertensive Diseases

I. The Influence of Aging on Cerebral Circulation and Metabolism

Abstract

The values concerning the cerebral circulation and metablism of 24 healthy normotensive subjects and 51 patients with essential hypertension were measured, for studying the influence of aging on those functions, and also the significance of the complication of cerebral arteriolosclerosis, so closely related with aging, was discussed.
1. In any group of normotensive as well as of hypertensive subjects, cerebral vascular resistance (CVR) tended to increase and cerebral blood flow (CBF) and cerebral oxygen consumption (CMRO₂) to decrease with advance in age. This tendency was more evident in the latter than in the former group.
2. The mean values concerning the cerebral circulation and metabolism of the patients with essential hypertension were studied in comparison with those of normotensive subjects, and it was found that the mean arterial blood pressure (MABP) and CVR were found markedly higher in the former, whether of the middle or old age, than those of the latter subjects of the same age range. The mean CBF and CMRO₂ were not found significantly different in the normotensive and the hypertensive subjects of the middle age groups, but in the old age groups those values were slightly lowered in the subjects with essential hypertension.
3. When the patients with essential hypertension are complicated with retinal arteriolosclerosis, in general the increase in CVR was more prominent, in particular, more so in old patients, and simultaneously, in not a few cases, the disturbance in cerebral circulation and metabolism was more evident, CBF and CMRO₂ showing a tendency of lowering.