Acute Arrest of Cerebral Circulation in Man

Numerous investigations have been concerned with the effects of acute arrest of cerebral circulation in animals. The earlier workers' studied the effects of ligation of the cerebral arteries . More recently, observations have been made on the effects of temporary occlusion of the chief cerebral arteries 2 and of temporary cessation of the heart beat .$ Using the method of occlusion of the chief cerebral arteries, Sugar and Gerard' measured the survival time for different regions of the cat brain by the persistence of spontaneous action potentials. A careful study of the changes in function and structure of the brain of the cat resulting from temporary occlusion of the pulmonary artery was reported on by Weinberger, Gibbon and Gibbon .b These methods involved one or another of the following complications anesthesia ; surgical procedures at the time of arrest of circulation in the brain ; incomplete arrest of circulation as a result of failure to occlude the anterior spinal artery ; arrest of circulation in vital organs outside the central nervous system, and difficulty of determination of the exact moment of cessation of the heart beat . For quantitative study a technic was utilized which produced sudden complete arrest of blood flow in the brain of the unanesthetized animal without the per-