The effects of critical stenosis of the carotid artery, alone or in combination with occlusion of other vessels supplying the brain, on cerebral circulation remain unresolved. Compromised cephalic blood flow has been implicated as a major factor in the etiology of transient ischemic attacks, but data to support or refute this concept are equivocal. We have directed our investigations along this line selecting an animal in which the cerebral circulation is most comparable to that of man. In the baboon, the internal carotid and vertebral arteries characteristically represent the exclusive supply for cerebral perfusion.1 The anatomy of the circle of Willis in the baboon is at variance with that of man in one regard, namely that the anterior cerebral arteries arise independently from the internal carotid arteries and fuse in the midline to form a single anterior cerebral artery which then supplies the medial surface of both hemispheres.
Methods