Ischemic Cerebral Edema and the Blood-Brain Barrier

Abstract

Distributions of pertechnetate, albumin, sodium, and antipyrine in cat brains were studied four hours to 20 days after occlusion of one middle cerebral artery (MCA). Brain:blood ratios for each substance were greatest in infarcted tissue and least in nonischemic tissue. Higher ratios for pertechnetate than for albumin in nonischemic tissue indicated a normal extravascular distribution of pertechnetate. In ischemic and infarcted tissue, brain:blood ratios for pertechnetate, albumin, and sodium were increased as early as four hours after MCA occlusion, were maximal at four to seven days, and remained high (for pertechnetate) until 20 days. Distributions of water after MCA occlusion did not have the same temporal or spatial characteristics as distributions of the other substances; thus, ischemic cerebral edema is not related solely to disruptions of the blood-brain barrier or to extravascular accumulations of sodium and protein.