Acute Stroke Therapy: Highlighting the Ischemic Penumbra

The ultimate goal of acute stroke therapy is to rescue the affected brain tissues that are salvageable and to avoid or minimize the potential neurological outcome. The current available thrombolytic treatment is limited by the narrow therapeutic time window due mainly to the progressively reduced rescuable tissues (ischemic penumbra) after the onset of stroke. Therefore, preserving penumbral tissue can potentially widen the therapeutic time window and improve the quality of acute stroke therapy. Hence, ischemic penumbra is the key to stroke pathology and treatment. In this chapter, the basic concept of ischemic penumbra is examined and this is followed by the discussion of the identification and evolution of penumbral tissue in animal stroke models and stroke patients. Finally, the possible mechanism of penumbral cell death and the importance of preserving penumbral tissue in the acute stroke therapy are discussed.