Tentorial Dural Arteriovenous Fistulas as a Cause of Thalamic Edema: 2 Cases of an Important Differential Diagnosis to Consider

The differential diagnosis for bilateral thalamic edema is extensive and includes vascular, neoplastic, metabolic, and infectious causes. Of the vascular causes of thalamic edema, arterial and venous infarctions are well-documented, but dural arteriovenous fistulas (dAVFs) are a relatively uncommon and widely underrecognized cause of thalamic edema. Dural AVFs are notoriously difficult to diagnose clinically, especially in the absence of hemorrhage, and cross-sectional imaging findings can be subtle. This can result in a delayed diagnosis, and occasionally, an invasive biopsy for further clarification of a purely vascular disease. In this review, we detail our experience with the imaging diagnosis of dAVF as a cause of thalamic edema and present a short differential of other vascular causes.