[A case of dural arteriovenous malformation associated with progressive dementia showing marked improvement with endovascular treatment].

An 81-year-old man was admitted with a 3-month history of progressive dementia. Neurological examination revealed marked dementia, parkinsonism and myoclonus in his extremities. His cerebrospinal fluid examination was normal. An electroencephalogram showed a mildly slowed background. Computed tomography (CT) disclosed diffuse low-density areas in bilateral cerebral white matter. Contrast-enhanced CT demonstrated vermiform enhancement of engorged cortical veins, suggesting increased pressure of the venous system. Magnetic resonance imaging (MRI) disclosed diffuse high-intensity areas in bilateral cerebral white manner on T2-weighted images, and abnormal flow-voids presenting venous congestion on proton-density images. Cerebral angiography revealed arteriovenous malformation (AVM) fed by four branches of the right external carotid artery with retrograde drainage into the right transverse sinus, superior sagittal sinus, and dilated cortical veins. The ipsilateral sigmoid sinus was not visualized. After transarterial embolization, transvenous embolization of the right transverse sinus was performed. These treatments resulted in a marked clinical improvement. We emphasize the role of AVM as a cause of progressive dementia.