Rapidly progressive dementia caused by a superior sagittal sinus dural arteriovenous fistula: a case report.

We describe the case of a 72-year-old man who presented with dementia that had progressed rapidly over a few months. Laboratory analysis of blood and cerebrospinal fluid (CSF) showed no abnormalities, with the exception of a slightly increased CSF protein level. Results of routine magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) and magnetic resonance angiography (MRA) were unremarkable. However, detailed neuroimaging studies including contrast-enhanced T1-weighted MRI and conventional angiography revealed a superior sagittal sinus (SSS) dural arteriovenous fistula (DAVF). After endovascular embolization and surgical interruption of all arteries feeding the DAVF, the dementia reversed. We should be aware of the possibility of DAVF as the cause of rapidly progressive dementia even if routine MRI reveals no or only minimal abnormality.