From the Guidelines
Yes, Dural Arteriovenous Fistulas (DAVFs) can cause intracranial hypertension.
Mechanism and Presentation
DAVFs are abnormal connections between arteries and veins within the dura mater, the tough outer membrane covering the brain. When these fistulas develop, they can disrupt normal venous drainage patterns in the brain, leading to increased venous pressure. This venous hypertension can impair cerebrospinal fluid (CSF) absorption at the arachnoid granulations, resulting in elevated intracranial pressure 1. The mechanism typically involves venous sinus stenosis or occlusion due to the high-flow arteriovenous shunting from the DAVF. Patients may present with symptoms typical of intracranial hypertension including headaches, papilledema, pulsatile tinnitus, and visual disturbances.
Diagnosis and Treatment
Diagnosis of DAVF often involves imaging studies such as MRI or angiography to visualize the abnormal connection between arteries and veins. Treatment approaches include endovascular embolization, surgical disconnection of the fistula, or radiosurgery, depending on the location and complexity of the DAVF 1. Addressing the underlying DAVF is essential for resolving the intracranial hypertension, as temporary measures like CSF diversion or acetazolamide therapy only provide symptomatic relief without treating the root cause of the pressure elevation.
Key Considerations
- Intracranial hypertension due to DAVF can lead to significant morbidity and mortality if not properly managed.
- Early diagnosis and treatment are crucial to prevent long-term complications and improve quality of life.
- The choice of treatment should be individualized based on the patient's specific condition, the location and complexity of the DAVF, and the presence of any associated symptoms or complications. Given the potential for DAVFs to cause intracranial hypertension, prompt evaluation and management by a multidisciplinary team of healthcare professionals, including neurologists, neurosurgeons, and radiologists, is essential to optimize patient outcomes.
From the Research
Dural Arteriovenous Fistula (DAVF) and Intracranial Hypertension
- DAVF can cause intracranial hypertension due to impairment of cranial venous outflow 2
- Venous hypertension is a key factor in the development of intracranial hypertension in patients with DAVF 2, 3
- The clinical severity of DAVF is determined by venous hypertension, and evaluation of intracranial venous pressure is important in making decisions concerning treatment 4
Types of DAVF and Intracranial Hypertension
- Type II DAVF (drainage into a sinus with abnormal retrograde venous drainage into sinuses or cortical veins) is more likely to present with intracranial hypertension than Type I DAVF (drainage into a sinus with normal antegrade flow direction) 2
- Cognard type 1 DAVF can also occur after venous sinus stenting (VSS) for presumed idiopathic intracranial hypertension (IIH) 5
Treatment and Outcomes
- Treatment of DAVF can significantly enhance the increase in regional cerebral blood flow (rCBF) due to acetazolamide challenge 4
- Endovascular treatment, including arterial or transvenous embolization, and/or surgery, may be necessary to obliterate the fistula or reduce the arterial flow and restore normal cerebral venous drainage 2
- Symptom control can be achieved in a high percentage of treated patients, with a low risk of complications and no cases of intracerebral hemorrhage (ICH) or DAVF-related mortality 6