Overview
Dural arteriovenous fistulas (dAVFs) are abnormal connections between an artery and a vein in the tough covering over the brain or spinal cord (dura mater). This rare condition may occur in the brain, spinal cord, or other areas of the body. dAVFs tend to develop later in life (50 to 60 years of age) and are not typically inherited genetically. Although some cases have known causes, it is thought that those involving large brain veins usually form due to narrowing or blockage of one of the brain's venous sinuses, which typically route circulated blood from the brain back to the heart. Symptoms may include sudden, severe headache, nausea, vomiting, weakness or numbness on one side of the body, difficulties in speaking or understanding speech, loss of vision, double vision, and balance difficulties.
Understanding the disease
Symptoms
The symptoms of dural arteriovenous fistulas (dAVFs) can be characterized as either aggressive or benign. Aggressive symptoms can result from bleeding in the brain (intracerebral hemorrhage) or non-hemorrhaging neurological deficits (NHNDs). Symptoms may include:
- Sudden, severe headache
- Nausea
- Vomiting
- Weakness or numbness on one side of the body
- Difficulties in speaking or understanding speech
- Loss of vision
- Double vision
- Balance difficulties
- Seizures
- Facial pain
- Dementia
- Parkinsonism
- Coordination issues
- Burning or prickling sensations
- Weakness
- Apathy Benign symptoms are usually not associated with bleeding in the brain or neurological deficits. They may include:
- Headaches
- Pain in the head or neck
- Tinnitus (ringing in the ears)
- Vertigo (dizziness) It is important to note that some people with dAVFs may not have any symptoms at all.
Risk Factors
The risk factors for developing dural arteriovenous fistulas (dAVFs) include genetic predisposition to blood clots in the vein (vein thrombosis) due to abnormalities in blood clotting, which may increase the risk for blockage or narrowing of vein sinuses. However, it's important to note that dAVFs tend to occur later in life (50 to 60 years of age) and are not typically passed on genetically from parent to child.
Development
Dural arteriovenous fistulas (dAVFs) develop as abnormal connections between an artery and a vein in the tough covering over the brain or spinal cord (dura mater). They can occur spontaneously or as a result of identifiable causes such as traumatic head injury, infection, previous brain surgery, venous thrombosis, or tumors. It is thought that dAVFs involving large brain veins usually form due to narrowing or blockage of one of the brain's venous sinuses, which normally route circulated blood from the brain back to the heart. The risk factors for dAVFs include genetic predisposition to blood clots in the vein (vein thrombosis).
Assessment and Diagnosis
Triage
If you suspect a dural arteriovenous fistula (dAVF), you should seek immediate medical attention if you experience symptoms such as shortness of breath, chest or arm pain, or signs of a stroke, such as face drooping, arm weakness, or difficulty speaking. It is important to consult your doctor if you have other concerning symptoms as well. Early detection and treatment are crucial for managing dAVF and preventing potential complications.
Diagnosis
To diagnose dural arteriovenous fistulas, your doctor may recommend diagnostic imaging tests such as noncontrast head computerized tomography (CT) and magnetic resonance imaging (MRI). Cross-sectional imagery from these tests can show fluid buildup and any bleeding caused by the fistula. Angiography is considered the most reliable and definitive tool for diagnosing dAVF, as it provides detailed information on the number of fistulae, their location, and the structure of the blood vessels involved.
Management and Treatment
Complications
Potential complications of dural arteriovenous fistulas (dAVFs) include:
- Stroke: dAVFs can lead to brain ischemia (reduced blood flow) or hemorrhage, which can cause a stroke.
- Transient ischemic attacks (TIAs): These are temporary interruptions of blood flow to the brain, often causing sudden weakness, numbness, or difficulty speaking.
- Seizures: dAVFs can cause seizures due to abnormal blood flow and increased pressure in the brain.
- Brain damage: Chronic dAVFs can cause progressive brain damage due to long-term ischemia (reduced blood flow) or hemorrhage.
- Increased risk of aneurysm or arteriovenous malformation: dAVFs may increase the risk of developing other vascular abnormalities, such as brain aneurysms or arteriovenous malformations.
- Treatment complications: Surgical or endovascular interventions to treat dAVFs can have risks, such as bleeding, infection, or damage to surrounding brain tissue.
- Recurrence: Although rare, dAVFs can recur after treatment, particularly if the underlying cause remains unaddressed. It's important to note that the severity and likelihood of complications can vary depending on the individual case and the location, size, and type of the dAVF. Consult with a medical professional for personalized advice and management strategies.
Treatment
Treatment for dural arteriovenous fistulas (dAVFs) typically involves endovascular procedures, stereotactic radiosurgery, or surgery. These options aim to block blood flow to the dAVF, disconnect or remove it to prevent further complications. It is essential to consult with a medical professional to determine the most appropriate treatment for each individual case.