[Transcranial Doppler curve analysis. On the pathophysiology of unilateral carotid stenoses].

Vascular reactivity to changes in arterial CO2 content can be measured by analysis of Doppler curves in the middle cerebral artery (MCA). Vascular reactivity indicates the capability of the cerebrum of controlling peripheral resistance. In patients with threatening cerebrovascular disease (CVD) vascular autoregulation may be reduced. The circle of Willis plays a central role in the pathophysiology of unilateral high-grade ICA-stenosis. Previous classification of the degree of stenosis or of the clinical stage does not allow to describe the actual pathophysiology or prognosis of CVD sufficiently.