ABSTRACT
It is, first of all, important to address the merits and limitations of the flow threshold approach to cerebral ischemia. The main benefit has been, and continues to be, the insights gained into the pathophysiology of ischemic brain injury and the implications this has on the clinical care of stroke patients. Nonetheless, emphasizing thresholds in ischemia may imply that absolute CBF is the sole determinant of tissue injury, whereas in fact this is not true. Some biological processes, such as protein synthesis (vide infra) are perturbed during ischemia at CBF levels that are very close to normal. Such levels are not known to disturb the energy state of brain tissue and are commonly encountered outside the context of acute stroke, apparently exerting no effect.
