Arteriovenous malformation is characterized by what type of condition in the brain?

Arteriovenous malformation (AVM) refers to a specific condition in which there is an abnormal tangle of blood vessels, specifically arteries and veins, that disrupts normal blood flow and oxygen delivery to the brain. In a typical vascular structure, arteries carry oxygen-rich blood from the heart to the brain, while veins return deoxygenated blood back to the heart. In AVMs, however, the direct connections between arteries and veins bypass the usual network of capillaries, which can lead to various complications.

The presence of these tangled vessels can lead to a number of serious consequences, such as increased pressure in the veins, which may eventually cause them to rupture—a significant risk factor for hemorrhagic strokes. While AVMs can lead to conditions like a hemorrhagic stroke due to the rupture of these vessels, the defining characteristic of an AVM is the tangle of arteries and veins themselves, which is why that option is identified as the correct one. Understanding this is crucial in the context of brain vascular malformations and their potential clinical implications.