Cerebral Dural Arteriovenous Fistulas (dAVFs) are abnormal connections between arteries and veins within the dura mater, the protective covering of the brain. dAVFs can develop later in life due to various factors, such as trauma, infections, or blood clot-related complications. These abnormal connections lead to increased pressure in the venous system, which can cause neurological symptoms or, in severe cases, life-threatening complications like brain hemorrhages.
The severity of a dAVF depends on its location, size, and the pattern of venous drainage. Some dAVFs have benign courses and cause mild symptoms like headaches or tinnitus (a pulsing sound in the ear), while others can be aggressive, leading to seizures, neurological deficits, or stroke-like symptoms. The key concern with high-risk dAVFs is their ability to drain into deep cerebral veins, which increases the chance of brain swelling or hemorrhage.
The exact cause of dAVFs remains unclear, but they are often associated with conditions that increase venous pressure, such as venous sinus thrombosis (a clot in the brain’s venous system) or previous head injuries. Some theories suggest that abnormal angiogenesis (new blood vessel formation) in response to injury may play a role in their development. In many cases, dAVFs are discovered incidentally during imaging for unrelated neurological conditions, but they require careful evaluation to determine their potential risk.