Progressive Cognitive Decline With Bithalamic and Basal Ganglia Lesions Caused by Dural Arteriovenous Fistula.

A 55-year-old previously healthy man was admitted because of a 3-month history of progressive cognitive decline with Mini-Mental State Examination score 17, characterized mainly by apathy, memory impairment, speech disturbances, anosognosia, and hypersomnia. MRI revealed engorged veins and T2 hypersignal in bilateral thalamus and basal ganglia, with no restricted diffusion on diffusion-weighted imaging (Figure 1). Angiography revealed an anterior skull base dural arteriovenous fistula (DAVF) draining through the inferior sagittal sinus to the internal cerebral and basal vein of Rosenthal with straight sinus occlusion (Figure 2). The clinical picture is explained predominantly by bithalamic venous congestion due to the DAVF and occlusion of the straight sinus.(1,2)