THE EVALUATION OF INTRACRANIA AND EXTRACRANIAL CIRCULATION IN SUBCLAVIAN-STEAL-SYNDROME

Objective To compare the efficacy of transcranial Doppler ultrasound ( TCD) and digital subtraction angiography (DSA) in identifying the clin ical and hemodynamic relationship between intra- and extra-cranial cir culation and subclavian areal syndrome. Methods Sixteen patients were collected. The intra- and extra-cranial arteries were insonated with D oppler ultrasound, DSA and brain CT were performed in all patients. Th e relationship between the grade of arterial stenosis showing in DSA a nd the flow direction showing in TCD was studied. Results TCD showed r eversal flow of the vertebrobasilar artery in 13 patients, normal flow in 3, which was influenced obviously by fist-clenching. In the hypere mia test, the flow velocity and the direction changed significantly in all patients. The steal phenomenon of the middle cerebral artery (MCA ) was coincident with that of the arterial cerebral artery (ACA) in 2 cases. Stenosis of MCA or ACA was found in 5 cases (31%). Nine patient s were treated with arterial bypass or angioplasty. TCD was performed during the follow-up. Conclusions Reversal flow of the vertebral arter y may occur in rest or only in exercise, depending on the grade of sub clavian arterial stenosis. Hyperemia test is the most sensitive index. It is necessary to monitor blood flow in the MCA and basilar artery i n hyperemia test. The coexistence of intra- and extracranial arterial stenosis is common.