DYNAMIC COMPONENT OF INTERNAL CAROTID-ARTERY STENOSIS IN PATIENTS WITH CEREBROVASCULAR-DISEASE - EFFECTS OF NIFEDIPINE

By means of Doppler spectral analysis, it was shown that internal caro tid artery stenosis has a dynamic component that determines the possib ility of changes in the area of stenosis under various influences. It was demonstrated that cold pressor test may increase the area of steno sis in some patients for up to 3-5 hours. In such cases, reduction of volume blood flow in the commun carotid artery and decrease of cerebra l blood flow in the ipsilateral hemisphere of the stenosis are observe d. Such a response was effectively prevented by nifedipine. At the sam e time, nifedipine can itself change the area of stenosis in some pati ents examined. In 31 cases it decreased the area by 22.9 + 5.9% and in 11 cases it increased it by 26.4 + 7.7%. When the decrease in the are a of stenosis was observed, nifedipine enhanced cerebral blood flow. H owever, it provoked a depression of cerebral blood flow in the patient s in whom the area of stenosis was increased. The data obtained disclo se one of the reasons of the variability of therapeutic effects of vas odilators in patients with cerebrovascular disorders.