Experimental observations on animals in which complete or temporary arrest of the cerebral circulation has been effected indicate that profound clinical and pathologic sequelae are consequent on the procedure. Gildea and Cobb1 discovered that periods of total anemia of no longer than ten minutes resulted in severe, permanent lesions of a necrobiotic character in the cerebral cortex of the cat. Using the dog as subject, Kabat and Dennis2 produced unconsciousness, cessation of respiration and total abolition of reflexes by obstruction of the cephalic blood flow for fifteen to twenty minutes. The chronic picture was one of virtual decerebration.
The exact human counterpart of these controlled investigations is necessarily difficult to find. Several cases have been reported, however, in which sudden, and presumably complete, cerebral anemia was followed by the development of neuropsychiatric syndromes. Postmortem examination revealed the expected irreparable and extensive damage to the brain. The factors productive