From the Guidelines
Yes, Dural Arteriovenous Fistulas (DAVFs) can cause intracranial hypertension. 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 blood flow patterns and lead to increased pressure within the skull. This occurs primarily through two mechanisms: by causing venous hypertension when the fistula drains into cortical veins, or by obstructing venous outflow from the brain. The increased venous pressure can impair cerebrospinal fluid absorption at the arachnoid granulations, leading to elevated intracranial pressure.
Key Points to Consider
- DAVFs can lead to intracranial hypertension due to venous hypertension or obstructed venous outflow 1.
- Patients with DAVF-induced intracranial hypertension may experience symptoms such as headaches, visual disturbances including papilledema, pulsatile tinnitus, and other symptoms typical of increased intracranial pressure.
- Treatment depends on the location and classification of the DAVF but typically involves endovascular embolization, surgical disconnection, or radiosurgery to close the abnormal connections.
- Addressing the DAVF directly is essential, as standard intracranial hypertension treatments like acetazolamide or CSF shunting may not be effective without treating the underlying vascular abnormality.
Clinical Implications
The presence of DAVF as a cause of intracranial hypertension highlights the importance of a thorough diagnostic workup, including imaging studies, to identify the underlying cause of symptoms. Given the potential for DAVFs to cause significant morbidity and mortality, early recognition and treatment are crucial. The most recent study 1 supports the notion that DAVFs can be a cause of intracranial hypertension, emphasizing the need for clinicians to consider this diagnosis in patients presenting with symptoms of increased intracranial pressure.
From the Research
Dural Arteriovenous Fistula (DAVF) and Intracranial Hypertension
- DAVF can cause intracranial hypertension due to venous hypertension, which is a result of impaired cerebral venous drainage 2, 3, 4.
- The most common mechanism is retrograde leptomeningeal venous drainage, causing venous engorgement and impairment of cerebral venous drainage 2.
- Stenosis or thrombosis of the dural sinus can worsen venous hypertension, leading to increased intracranial pressure 2, 3.
- Clinical symptoms of increased intracranial pressure include headache, papilledema, bruit, seizures, vertigo, visual deficits, and impairment of cognitive functions 2, 3, 4.
Angiographic Signs of Venous Hypertension
- Angiographic criteria for venous hypertension include delayed circulation time, venous engorgement, and abnormal visualization of the cerebral veins 2.
- Endovascular treatment can lead to the disappearance of angiographic signs of venous hypertension and clinical cure in patients with DAVF 2, 3.
Rare Complications of DAVF
- DAVF can cause progressive dementia due to venous hypertension in the cortex or bilateral thalami 5.
- DAVF formation can occur after venous sinus stenting for idiopathic intracranial hypertension, possibly due to hemodynamic alterations or increased inflammation 6.
Treatment and Outcome
- Endovascular treatment, including arterial or transvenous embolization, and/or surgery, can be effective in treating DAVF and reducing intracranial hypertension 2, 3, 5.
- Patients with DAVF require continuous clinical and angiographical follow-up to monitor for recurrence or progression of the disease 3.