What happens to the brain tissue as a consequence of ischemic stroke?

In the case of an ischemic stroke, the brain tissue experiences a lack of blood flow, which leads to a decrease in oxygen and nutrient delivery necessary for cellular metabolism. As a result, the affected brain tissue starts to undergo necrosis, which is a form of cell injury that results in cell death. When the brain cells are deprived of oxygen (a condition known as hypoxia), they cannot perform their normal functions, and without timely restoration of blood flow, irreversible damage occurs. Necrotic tissue is characterized by cell death and the inability to regenerate, leading to the formation of an area of infarction within the brain.

This is why the correct choice is that the brain tissue becomes necrotic following an ischemic stroke. The other options, such as hypertrophy, hyperplasia, or remaining unaffected, do not accurately describe the pathological changes that occur in brain tissue due to ischemic processes.