NONINVASIVE TESTING OF DYNAMIC COMPONENT OF INTERNAL CAROTID-ARTERY STENOSIS IN PATIENTS WITH CHRONIC CEREBROVASCULAR-DISEASE

By means of Doppler spectral analysis it was shown that internal carot id artery stenosis has a dynamic component that determines the possibi lity of changes in the area of stenosis under various influences. It w as found that the cold pressor test may increase the area of stenosis in some patients for up to three to five hours. In such cases reductio n of blood flow volume in the common carotid artery and decrease of ce rebral blood flow in the ipsilateral hemisphere of the stenosis are ob served. Such a response was effectively removed by nifedipine. At the same time nifedipine itself is capable of changing the area of stenosi s, either enlarging or reducing it. In the first case enhancement of b rain blood supply is observed, and in the second case, its decrease. T he data obtained disclose one of the reasons for the variability in th erapeutic effects of vasodilators in patients with cerebrovascular dis orders.