Stroke therapy research is generally based on the implicit assumption that one or, at most, a few factors or processes control the progressive damage that occurs in the early hours of brain ischemia. There is a finite probability that this assumption is inherently wrong. Among the many factors participating in progressive injury, none may be dominant or controlling, and the factors may act instead as a network of minor causes. If this possibility should turn out to be true, it would seriously degrade the likelihood of success of the "conventional" stroke therapy approaches.
The ischemic injury zone, which is the target for therapy, is viewed as having a densely ischemic core that would only respond to therapy instituted within minutes of the ictus. Surrounding the core is an "ischemic penumbra," a shell of tissue in a metastable state that is potentially viable if properly treated. The goal is to prevent