Dural arteriovenous fistula, a rare cause of rapidly progressive dementia in a patient with bilateral thalamic lesions: a case report

There are many causes of bilateral thalamic lesions, but few cases of dural arteriovenous fistula (DAVF) associated with such lesions have been reported previously. Here, we describe an adult man with reversible rapid progressive dementia (RPD) in whom bilateral thalamic lesions were caused by a DAVF that had six supply arteries and drained into both the venous sinus and cortical veins. A 53-year-old man presented with memory decline and abnormal behavior. Head computed tomography (CT) revealed insignificant low density in the bilateral thalami and high density in the right occipital lobe. Brain magnetic resonance imaging showed hyperintensities in the thalami on T2-weighted images. Magnetic resonance venogram revealed no sign of the straight sinus, but multiple tortuous vessels in the cistern of the vein of Galen. Digital subtraction angiography revealed DAVFs near the tentorium cerebelli draining into the vein of Galen, which caused the vasogenic oedema of the thalami. The patient was then treated by transarterial embolization of the feeders. He gradually recovered after the surgery. RPD with bithalamic lesions caused by DAVF is rare but reversible. Therefore, the early recognition and intervention of DAVFs is crucial for the good prognosis of patients so that fistulas can be embolized in time.