Medial tentorial dural arteriovenous fistula: A rare cause of bithalamic oedema

Abstract

A 39-year-old man was admitted after 1 week of headaches and cognitive changes. CT scan showed bithalamic hypodensities, corresponding to bithalamic vasogenic oedema. Punctuate hemorrhage was present, with foci of thalamic enhancement. CT angiography raised the suspicion of arteriovenous shunt. Digital subtraction angiography confirmed a medial falcotentorial dural arteriovenous fistula. Complete embolization was performed using liquid embolic agent. Although tentorial dural fistulas have already been described as a cause of bithalamic oedema and subacute dementia, they are not generally included in pathologies implied in this radiologic pattern.

Keywords: Bithalamic oedema; Dural arteriovenous fistula; Embolization; Fistula; Neuroradiology.

Fig. 1

Noninvasive Imaging A: Plain CT scan showing bithalamic symmetrical hypodensities B: Baseline MRI showing bithalamic FLAIR hyperintensities C: Diffusion MRI depicting increased bithalamic apparent diffusion coefficient (ADC) D: Punctuate hemorrhage in right thalamus on T2* E: Gadolinium enhanced sequence showing small foci of bithalamic patchy enhancement F: Arterialized superior vermian vein (white arrow) draining into vein of Galen (dotted white arrow) and subsequently into internal cerebral vein (black arrow).

Fig. 2

Digital Subtraction Angiography (DSA) A and B: Lateral (A) and anteroposterior (B) arterial phase showing the fistulous plaque (white arrow), the arterialized superior vermian vein (dotted white arrow) and vein of Galen (black arrow) C and D: Small contribution of the medial tentorial branch from the left middle meningeal artery (white arrow) E: Lateral venous phase of left vertebral artery injection showing filling defect of the anterior part of straight sinus, related to deep venous thrombosis F: Post embolization non-substracted image showing liquid-embolic cast in the arterial feeders, in the fistulous plaque, but away from the vein of Galen.