What characterizes a dural arteriovenous (AV) fistula?

A dural arteriovenous fistula is specifically characterized by a direct connection between a meningeal artery and a meningeal vein, which allows for abnormal blood flow from the artery to the vein. The unique aspect of this condition is that it bypasses the normal capillary bed system, leading to an increase in venous pressure and potential complications such as hemorrhage or neurological deficits.

The formation of this fistula can result from various factors, including trauma or spontaneous occurrences. Typically, the meningeal artery that creates the fistula is a branch of either the external or internal carotid arteries, and the affected vein is usually one of the cerebral or dural veins. This direct connection is crucial to understanding the pathophysiology involved, as it can significantly affect venous drainage and lead to increased intracranial pressure.

In contrast, the other choices describe different conditions or anatomical relationships that do not fit the specific definition of a dural AV fistula. For instance, a connection between two arteries is indicative of a vascular malformation but does not encompass the characteristics of an arterovenous fistula. A blockage in the dural sinus refers to an obstruction that can have its own set of complications but is unrelated to the direct arterial