MANY experimental studies1-4 of the cerebral circulation in experimental animals have been reported as using the technique of fall of pressure drops in the lingual artery and in the middle cerebral arteries after the occlusion of one or more of the afferent vessels supplying the circle of Willis. Our previous work was oriented chiefly to the physiological aspects of the problem. In this paper are discussed the clinical implications of studies in which we investigated the hemodynamics of the circle, with special regard to the vertebral basilar system as a collateral pathway following the occlusion of one or both of the carotid arteries. Data obtained from the normal dog have been compared with that from animals in which changes were produced in the circle of Willis simulating the conditions seen in human pathology.
We first studied the relationship between pressure in the lingual artery after the occlusion