Current concepts in cerebral protection.

In the past, physicians viewed ischemic injury as an irreversible event. Modern science has shown that this view is incorrect and that ischemic neuronal damage is an ongoing, active process that might be amenable to various therapies. Figure 2 illustrates some of the possible sites where these therapies might be active. Pending evidence of their effectiveness, cerebral protection can best be achieved by maintaining adequate CPP and CBF during periods when patients are at risk for cerebral ischemia, restoring perfusion after ischemia occurs, and optimizing the metabolic milieu of the ischemic penumbra.