[Changes in circulation of the blood in cerebral arteries in relation to age]

The authors examined 12 people under 40 years and 12 above 40 years, mostly healthy volunteers. They investigated the rate of blood flow in the median cerebral artery after compression of the homolateral and contralateral internal carotid. They found that in more advanced age the rate of flow in the mentioned arteries is significantly reduced. During compression tests in more advanced age the decline in the flow rate is more marked in the median cerebral artery on the side of compression. In the other arteries the flow is promoted but the age dependence is not marked. The authors conclude from these findings that with advancing age the possibilities of autoregulation deteriorate more than those of the collateral circulation via Willis' circle.