Rapid cognitive decline: not always Creutzfeldt-Jakob disease

A patient with rapidly progressive cognitive decline over an approximately four month period was suspected to have sporadic Creutzfeldt-Jakob disease. Features thought to support this diagnosis included psychiatric symptoms (anxiety and depression), visual hallucinations and a visual field defect. However, the finding of papilloedema broadened the differential diagnosis. Although standard brain imaging and electroencephalography had shown only non-specific abnormalities, subsequent cerebral angiography disclosed an intracranial dural arteriovenous fistula.