We describe an unusual case of a dural AV fistula that presented with cognitive decline

Dural AV fistulas are abnormal, often clinically silent, connections between dural arteries and dural veins or venous sinuses, commonly associated with nearby venous sinus thrombosis. Progressive cognitive decline is a rarely described presentation of cerebral dural AV fistulas.

A 68 year old previously healthy man presented with rapid cognitive decline that began one week after travel to Vietnam.  He developed progressive confusion, day-night reversal, memory loss, and slowed speech and gait.  He was treated with steroids and intravenous immunoglobulin therapy at an outside hospital, then transferred to our institution due to lack of improvement.  On examination, he had impaired orientation, attention, naming, fluency, and comprehension.  He had akinetic mutism and frontal release signs. Magnetic resonance (MR) imaging of his brain showed bilateral thalamic T2 hyperintensities extending to the left splenium. MR angiogram was unremarkable. CSF studies showed white blood cells 0/4, glucose of 53, and protein of 91.  EEG showed diffuse slowing.  The initial concern was for Japanese Encephalitis Virus given his bithalamic lesions and travel history; however, the lack of preceding illness or CSF pleocytosis was puzzling.  A venous phase angiogram was obtained due to concerns that the injury was in a distribution consistent with venous infarction. The angiogram showed a grade III dural AV fistula associated with chronic straight sinus thrombosis.  The patient underwent glue embolization and was started on anticoagulation.

This patient’s rapid cognitive decline was likely due to progressive venous hypertension. This case highlights the importance of considering dural AV fistulas as an underlying cause for rapidly progressive dementia, as the discovery of a dural AV fistula may necessitate prompt endovascular therapy.