Intraventricular Hemorrhage due to a Distal Anterior Choroidal Artery Aneurysm Associated with an Arteriovenous Malformation in the Trigone

Objective: We herein describe a rare case of intraventricular hemorrhage (IVH) due to a distal anterior choroidal artery (AChA) aneurysm associated with an arteriovenous malformation (AVM) in the trigone of the lateral ventricle during early pregnancy. Case Presentation: At 8 weeks of pregnancy, a 36-year-old woman developed sensory aphasia and mild right hemiparesis due to a left lateral IVH. Digital subtraction angiography showed a peripherally located aneurysm branching from the medial perforating branch (MPB) of the plexal segment in the AChA associated with a micro-AVM in the trigone of the left lateral ventricle. Endovascular embolization was performed. A microcatheter was guided to a feeder branching out from the MPB. The aneurysm and the nidus, including the feeder, were occluded by 20% n-butyl-2cyanoacrylate (NBCA). However, right homonymous hemianopsia was apparent postoperatively, although the blood flow of the cisternal segment was preserved. Head MRI showed an acute infarction in the perfusion area of the AChA, including the internal capsule and optic radiation. Conclusion: We performed endovascular embolization to temporarily treat both the aneurysm and the nidus because the source of bleeding was unclear considering the hematoma position and angiographic features. Ischemic complications of the embolization for the aneurysm and the nidus with the preservation of the cisternal segment of the AChA are unusual.