[The extra- and intracranial correlations of cerebral hemodynamics].

The transcranial Doppler method, at the present, allow us to study, in non-invasive way, the cerebral haemodynamics and its changes in case of extra- and intracranial vascular disease. The correlations between the intracranial data, obtained by means the transcranial doppler, and the informations, received by the duplex Doppler ultrasound and the color doppler ultrasonography, permit us to effect a complete and correct assessment of the cerebral circulation and to indicate an efficient medical or surgical therapy. The valuation of the compensatory intracranial circulation and the cerebral vasodilatator capacity is very important to establish the degree of cerebrovascular damage. Finally the transcranial Doppler allow us an indirect valuation of the intracranial lesion of the circle of Willis.