This case illustrates an incidental finding characterized by a small sacular aneurysm arising from an arterial branch within the fourth ventricle. DSA study confirms to be a posterior inferior cerebellar artery aneurysm.

With regards to possible endovascular treatment options, these would include aneurysm occlusion and parent artery sacrifice (not favored given the very large territory supplied); stent-assisted coil embolization; and a stent without coils (flow diverting or otherwise). Other than the first of these options, all would require dual antiplatelet therapy, complicated by the current need for full anticoagulation (ceased and converted to clexane prior to this procedure). All options carry a moderate risk of PICA territory infarction.

Surgery to clip the aneurysm was proposed and performed without major complications.