What characterizes an embolic stroke?

An embolic stroke is characterized by the blockage of blood flow to the brain due to a blood clot that forms elsewhere in the body and then travels to the brain. This clot, known as an embolus, obstructs a cerebral artery, which results in ischemia, or a lack of blood flow, and can lead to brain tissue damage. This type of stroke often occurs when a piece of plaque or a blood clot from the heart dislodges and is transported through the bloodstream.

The other options describe different medical conditions. The first choice refers to a hemorrhagic stroke caused by a vessel rupture, leading to bleeding in the brain. The third choice relates to a neurotransmitter deficit, which is not a direct cause of embolic strokes but can affect brain function. The last option describes an infectious process that can lead to dysfunction but is not related to the vascular obstruction characteristic of embolic strokes. Thus, the correct answer encapsulates the key feature of an embolic stroke, focusing on the obstruction of blood flow due to a clot.