6th Edition of Neurology World Conference 2026

Abstract

Background/Objective: Torcular Herophili dural arteriovenous fistulas (DAVFs) are rare intracranial vascular malformations that can produce venous hypertensive encephalopathy (VHE), closely mimicking neurodegenerative or cerebrovascular disease. We report a case illustrating the diagnostic pitfalls of this condition and the reversibility of VHE following endovascular treatment. Methods/Case: A 70-year-old woman developed subacute, progressive motor slowing, gait instability, and cognitive decline over three months, initially attributed to lacunar ischaemia. Serial MRI showed progressive bilateral white-matter hyperintensity (Fazekas grade 2). Comprehensive investigation — CSF analysis, autoimmune encephalitis panel, MOG-IgG antibodies, oligoclonal bands, and toxicological screening — was unremarkable, and high-dose corticosteroids produced no benefit. She progressed to aphasia and inability to stand. Repeat contrast-enhanced MRI revealed early opacification of the left transverse sinus during the arterial phase, prompting digital subtraction angiography (DSA), which confirmed a torcular Herophili DAVF fed by the left middle meningeal artery and bilateral occipital arteries, draining into the torcular, straight sinus, left transverse sinus, and bilateral deep cerebral veins with retrograde deep venous reflux. Results: Transarterial embolization with ONYX achieved complete fistula obliteration. At one-month follow-up, MMSE improved from untestable to 23/30, with recovery of speech and mobility, and follow-up MRI demonstrated marked reduction in white-matter signal abnormality, confirming reversal of venous congestion. Conclusion: Torcular Herophili DAVFs can present as rapidly progressive dementia and Parkinsonism mimicking common neurodegenerative and cerebrovascular syndromes. A disproportionately progressive, treatment-refractory course — particularly the triad of cognitive decline, gait failure, and incontinence — should prompt neurovascular imaging. Early venous opacification on MRI is a key diagnostic clue, and DSA remains essential for diagnosis and treatment planning. Timely endovascular embolization can achieve substantial neurological recovery even after prolonged symptomatic deterioration, underscoring the value of maintaining a broad differential in atypical progressive encephalopathy. Keywords: dural arteriovenous fistula; torcular Herophili; venous hypertensive encephalopathy; endovascular embolization; dementia mimic; intracranial venous hypertension