Idiopathic middle meningeal artery and middle meningeal vein fistula presenting as temporal intraparenchymal hemorrhage

Middle meningeal artery (MMA) and middle meningeal vein (MMV) fistula is a rare lesion. Hemorrhagic propensity for this pathology has not been widely recognized. We encountered a case of idiopathic MMA-MMV fistula presenting as intracerebral hemorrhage. MMA and MMV showed a single fistula and the enlarged MMV coiled around the MMA, resembling a varix. We treated the case using endovascular techniques. This case highlights the anatomy along the course of the MMV and is unique, since no backward leptomeningeal drainage was observed. A bone defect in the meningeal groove on computed tomography and a “green caviar appearance” on angiography may be characteristic of this rare pathology.