Which of the following is NOT an example of an acute cerebrovascular emergency?

The accumulation of atherosclerotic plaque is not classified as an acute cerebrovascular emergency because it refers to a chronic condition that develops over time, leading to gradual narrowing of the arteries. This process can increase the risk of acute events, such as strokes, but the plaque itself does not represent an immediate, life-threatening condition like the other options listed.

In contrast, the rupture of a cerebral arterial aneurysm, stroke due to thrombus rupture, and embolic blockage of a cerebral artery all represent sudden and urgent medical situations. These events result in immediate impairment of blood flow to the brain and require prompt intervention to prevent irreversible damage or death. Thus, while atherosclerosis is a significant risk factor for cerebrovascular emergencies, it does not itself constitute an acute event.