# Cognitive Impairment Without Dementia: A Treatable Case of Dural Arteriovenous Fistula

## TL;DR

An elderly man with memory loss was found to have a rare brain condition called dural arteriovenous fistula, which was successfully treated and improved his cognitive symptoms.

## Contribution

This case highlights a rare but treatable cause of cognitive impairment unrelated to dementia.

## Key findings

- A low-flow dural arteriovenous fistula was diagnosed using MRI and angiography in a patient with memory loss.
- Cognitive symptoms resolved after treatment with transarterial embolization.
- DAVFs may be an underrecognized cause of mild cognitive impairment without dementia.

## Abstract

Dural arteriovenous fistula (DAVF) can present with a wide range of symptoms depending on its location and the degree of arteriovenous shunting. Rarely, they may manifest as cognitive impairment due to chronic venous dysfunction. This is the case of an elderly man evaluated for subacute onset of memory loss without dementia. Magnetic resonance imaging (MRI) of the brain revealed a subtle subarachnoid vascularity in the right occipital lobe, without cerebral edema or parenchymal abnormality. Digital subtraction angiography (DSA) confirmed a low-flow Borden type III DAVF, draining via an occipital cortical vein into the basal vein of Rosenthal and the vein of Galen. Subjective cognitive symptoms resolved following successful treatment with transarterial Onyx embolization. The role of DAVFs in mild cognitive impairment without dementia is likely underrecognized due to their rarity and inherent difficulties in diagnosis. This suggests a potential role for detailed cognitive evaluation in guiding the management of DAVFs.