Intracerebral Hemorrhage Caused by the Rupture of a Traumatic Pseudoaneurysm in the Middle Meningeal Artery

Hematomas caused by the rupture of a pseudoaneurysm in the middle meningeal artery (MMA) after trauma usually present as epidural hematomas. Intracerebral hemorrhage (ICH) is extremely rare. We reviewed ICH due to the rupture of MMA pseudoaneurysms. We found that in cases of acute ICH, a pseudoaneurysm was attached to the outer surface of the dura mater and associated with dura tear. In patients with acute ICH, the intraoperative rupture of a pseudoaneurysm developed just after bone flap removal. In cases of delayed ICH, pseudoaneurysms adhered to the inner surface of the dura mater. In patients with delayed ICH, the intraoperative rupture of a pseudoaneurysm developed during dura opening and hematoma removal. In situations of dura tear after trauma, the rupture of pseudoaneurysms might lead to ICH via a dura tear. Pseudoaneurysms that develop in the MMA after trauma may exert pressure and result in the thinning of the dura mater. In this case, pseudoaneurysms will adhere to the inner surface of the dura mater after several days or weeks. ICH might develop through both acute and delayed mechanisms following the development of pseudoaneurysms in the MMA. Clinicians should pay attention to the timing of such ruptures during operations for both acute and delayed ICH.