Reversible Thalamic Dementia Caused by Venous Hypertension of Bilateral Thalami Resulting from Multiple Intracranial Dural Arteriovenous Fistulas Successfully Obliterated by Endovascular Treatment using Liquid Embolic Materials: A Case Report and Literature Review

We describe a patient with multiple cranial dural arteriovenous fistulas (DAVFs) presenting with thalamic dementia. A 52-year-old man experienced progressive dementia and behavioral change for 1 month. Cranial computed tomography scan and magnetic resonance imaging (MRI) showed bilateral thalamic edema with subsequent hemorrhagic transformation. Cerebral angiography demonstrated multiple cranial DAVFs at the straight sinus and posterior part of the superior sagittal sinus. The symptomatic fistula was the straight sinus DAVF, Cognard Type II a + b, supplied by meningeal branches of the left superior cerebellar artery, the left ascending pharyngeal artery originating from the left occipital artery, and multiple tiny branches of the left occipital artery with retrograde venous drainage into the straight sinus and vein of Galen. In addition, there was probable thrombosis at the middle part of the straight sinus associated with anatomical variation of the dural venous sinuses at the torcular herophili. The patient underwent successfully endovascular treatments in a two-staged embolization using liquid embolic materials. The patient has gradually recovered and could get back to the activities of daily living at home within 2 months. Follow-up MRI of the brain at 6 months revealed nearly complete resolution of the bilateral thalamic congestion. Cerebral angiography, obtained 1 year after endovascular treatment, confirmed complete obliteration of both DAVFs. We also reviewed the literature of thalamic dementia caused by intracranial DAVFs.