Intracranial Dural Arteriovenous Fistula Presenting As Progressive Dementia and Parkinsonism

Background and aims: Dural arteriovenous fistula (DAVF) is a rare, but potentially treatable neurological condition, resulting from abnormal connections between meningeal arteries and dural sinuses. Parkinsonism with or without dementia has been reported as a presenting manifestation of DAVF. This case study aims to increase awareness of DAVF as one of the causes of rapidly progressive cognitive dysfunction and parkinsonism. Methods: 74-year-old man developed progressive parkinsonism with impaired cognition over ten months. Systematic workup for evaluation of rapidly progressive dementia included prion disease, neurodegenerative, autoimmune, infectious, toxic-metabolic and neoplastic disorders. Results: Brain MRI revealed T2 weighted image hyperintensities involving bilateral deep and subcortical white mater (Figure A). Moreover, some of these areas disclosed discrete hyperintensity on DWI corresponding to low values on ADC maps, reflecting cytotoxic edema secondary to ischemic injury (Figure B, C). In addition, the right transverse/ sigmoid sinus was markedly dilated as were the superficial veins of both cerebral and cerebellar hemispheres (Figure D, E). CT angiography of supra-aortic trunk and cerebral arteries disclosed abnormally enlarged and tortuous vessels in the subaracnoid space, corresponding to dilated cortical vein and abnormal right dural transverse/sigmoid venous sinuses including arterializations of contrast phase in the affected sinuses due to arteriovenous shunting (Figure F). Cerebral angiogram was not performed due to poor outcome. Unfortunately, the patient died soon of SARS-CoV2. Conclusion: DAVF is important for the differential diagnosis in patients with progressive dementia and parkinsonism. A high degree of clinical suspicion, detailed clinical examination and appropriate neuroimaging studies are crucial for early diagnosis of this disorder. (Figure Presented).