Case Presentation: We present a 68 year-old man, with a history of benign prostatic hypertrophy, who presented with several months of progressive personality changes and mild gait changes. His wife noticed he had become more introverted, and his gait had become more ataxic with prolonged ambulation. He also started having subtle memory problems. On physical, vital signs were normal. His neurologic exam was notable for mild decreased speech fluency, saccadic intrusions, and short-stepped gait. CBC and electrolytes were normal. HIV, RPR, Coccidioides, Cryptococcus, and Histoplasma antigens were negative. MRI brain revealed bilateral thalamic masses. Neurology and Neurosurgery were consulted and recommended MR spectroscopy, MRA and MRV brain. This imaging revealed dural arteriovenous fistula (dAVF) with persistent venous congestion involving the thalami. Subsequent cerebral angiogram showed dAVF in the branches of the vein of Galen. Attempted percutaneous closure was unsuccessful, so he underwent supracerebral craniotomy for resection of his dAVF. In follow-up, our patient was noted to be more engaged and conversant with others.
Discussion: The majority of intracranial dAVF are idiopathic. Modes of presentation include intracranial hemorrhage (ICH) and non-hemorrhagic neurological deficits (NHNDs), both attributed to cortical venous hypertension. One manifestation of NHND is progressive dementia resulting from venous hypertension in the bilateral thalami. dAVF-induced thalamic dementia occurs most often in men in their fifth to seventh decade of life. Presenting findings include deficits in memory, executive function, attention, ataxia, and aphasia that develop over weeks to months. MRI of the brain invariably demonstrates T2/FLAIR hyperintensities indicating thalamic edema. Endovascular or surgical treatment of dAVF is performed to disconnect cortical venous drainage, the portion of the dAVF responsible for dementia. Improvement in neurologic symptoms is seen within days of treatment, and full neurologic recovery is achieved over months.
Conclusions: This case demonstrates the importance for hospitalists to expand their differential diagnoses to include intracranial dural arteriovenous fistulas when faced with a patient with dementia and neurologic deficits. A thorough history, physical exam, and intracranial imaging were essential to diagnosing this patient correctly, allowing him to receive appropriate treatment that improved his symptoms and quality of life.