They are abnormal connections between an artery and a vein in the dura mater, which is the tough covering over the brain and spinal cord. They tend to occur later in life and most of them occur due to blockage or narrowing of the brain’s venous sinuses which drain the circulated blood back from the brain to the heart.
Symptoms may vary from severe headache with a varying degree of neurological disability to milder symptoms like mild hearing or vision loss. Initial evaluation may include a CT scan or an MRI. However, a cerebral angiography is still the most definitive tool for diagnosis of dAVF. Treatment includes Endovascular Embolization procedure performed by an interventional neuroradiologist. In the endovascular procedure, embolic agent like Onyx is used to embolize the fistulous venous sinus.