Diffuse white matter changes caused by dural arteriovenous fistula.

We present two patients with progressive dementia who showed diffuse white matter changes on magnetic resonance imaging (MRI) associated with dural arteriovenous fistula (DAVF) involving the transverse-sigmoid sinuses. Angiography of both patients revealed that DAVF was associated with multiple occlusive changes in the dural venous sinus. The associated occlusive changes isolated the straight sinus and the DAVF from the other venous sinuses, and concentrated the drainage of the DAVF in the straight sinus. We postulate that the venous hypertension of the straight sinus resulted in the venous ischemia of the white matter, diffuse white matter changes on MRI, and progressive neurological signs including dementia. Treatment of the DAVF reversed white matter changes and neurological signs. Associated with the venous sinus occlusions, the DAVF caused dementia with diffuse white matter changes due to the venous ischemia.