What characterizes an ischemic stroke?

An ischemic stroke is characterized by a blockage of blood flow to the brain. This blockage can occur due to a blood clot or other obstruction in an artery supplying blood to the brain, leading to a reduction in oxygen and nutrients that are essential for brain function. When the brain is deprived of these critical resources, it can result in brain cell damage or death, which manifests as various neurological deficits depending on the region of the brain affected.

Unlike the other possible answers, which describe conditions or mechanisms not specifically related to ischemic stroke, the blockage of blood flow is the defining feature. Bleeding associated with a brain vessel break describes a hemorrhagic stroke rather than ischemic stroke. Symptoms that resolve quickly can be indicative of a transient ischemic attack (TIA), which is not a full-blown stroke. Brain swelling from injury may occur following a stroke but is not a characteristic feature that distinguishes ischemic strokes specifically. Thus, the correct answer focuses on the fundamental cause of ischemic strokes: the obstruction of blood flow to the brain.