The beginning of stroke prevention by surgery.

Normal variations in the crossflow capacity of the Circle of Willis, and the effects of disease upon this and on the thromboembolic potential of the cervical carotid, together account for the clinical unpredictability of strokes. These two factors form a recurring theme in the history of stroke studies, from 1664 with the publication of Cerebri Anatome, to the duplex and computer-assisted scanning techniques of today. The path followed by the discoverers is traced from Hippocrates to Moniz and Miller Fisher, to show how their work led directly to the technique of carotid endarterectomy.