Abstract

A case of rapidly progressive dementia with diffuse leucoaraiosis on CT was attributable to a supratentorial dural arteriovenous malformation. Positron emission tomography (PET) showed low cerebral blood flow and high oxygen extraction ratio throughout the cerebral hemispheres indicating a state of chronic haemodynamic compromise which could predispose to the development of a vascular dementia. CT images of dilated intracerebral veins suggested that a venous drainage overload rather than a vascular steal phenomenon might be involved in the pathophysiology of the dementia of vascular origin.