Brain irreversibly injured

The clinical ischemic penumbra was described in a recent review by Moustafa and Baron [1]. They provided three criteria which are listed in Table 9.1. The clinical ischemic penumbra is the hypoperfused, but viable brain that is responsible for neurological deficits that can be reversed with the resumption of normal blood flow. This operational definition has value because it provides a physiologically relevant target for therapy, and the target may be identifiable by methods including CT and MRl as described in prior chapters. An important known property of the ischemic penumbra is that it is dynamic, that is, it becomes smaller with time, and conversely, the irreversibly injured brain (infarct core) grows with time. This is illustrated in Fig. 9.1. The... 

Fig. 9.1 The dynamic ischemic penumbra. This illustration demonstrates that the ischemic penumbra created by occlusion of the proximal right middle cerebral artery changes with time. Shortly after the MCA occlusion left) two regions of brain become manifest. The smaller region is designated as the core that represents irreversibly injured tissue that is destined to proceed to infarction. Surrounding this core is a region of hypoperfusion (the penumbra) that may give rise to significant neuro-...

The successful recanalization of an anterior circulation proximal artery occlusion will be of benefit to the patient only if it results in the prevention of infarction of brain tissue put at risk by that occlusion. Reperfusion into irreversibly injured tissue will not improve symptoms and may place the patient at risk for a hemorrhagic... 

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