[The pathophysiology of acute cerebral ischemia: clinical approach using physiologic imaging].

Physiologic imaging has recently allowed major new insights into the pathophysiology of acute ischemic stroke in man. The main observation concerns the major heterogeneity in pathophysiological patterns, with three situations being encountered: 1) cortical ischemic penumbra persisting up till 16 hrs post onset, which would represent an ideal therapeutic target; 2) early spontaneous reperfusion, predictive of favourable clinical and tissular outcome, and a priori requiring no specific therapy; and 3) early extensive necrosis, predictive of malignant hemispheric infarction. Physiologic imaging should soon become a fundamental tool in the evaluation of the individual pathophysiologic situation before a therapeutic decision about entry into trials is made.