Unraveling cerebral saccular aneurysm mimics: Case report and review of the literature

INTRODUCTION: Aneurysm mimics, such as an occluded cerebral artery, vascular loops or infundibular dilatations, should be beard in mind when planning a craniotomy for the treatment of an aneurysm. Although ischemic stroke caused by clot migration from an aneurysmal cavity has been described, an ischemic event should raise awareness of potential MCA branch occlusion instead of an aneurysm. RESEARCH QUESTION: We provided a scaffold that could be used to differentiate other saccular aneurysm mimics. We explored the current literature concerning ACM segment occlusions initially misdiagnosed as a saccular aneurysm. MATERIAL AND METHODS: We present the case of a 58 year old female who experienced a subarachnoid hemorrhage. CT angiography could not reveal an underlying aneurysm. She had a medical history of right carotid artery occlusion with secondary ischemic stroke and left spastic hemiparesis. An aneurysm of the right MCA was suspected and she was scheduled for explorative craniotomy. RESULTS: Peroperatively we did not encounter an aneurysm, although a thrombosed branch of the right MCA was noted. The most proximal part of the branch was still patent, mimicking a saccular aneurysm on angiographic records. DISCUSSION AND CONCLUSION: Aneurysm mimics can potentially expose patients to unnecessary exploratory craniotomies in the presumptive diagnosis of a saccular aneurysm. MRI 3D-CISS can be a helpful adjunct, since MRA and DSA are frequently not sufficient. Although ischemic stroke can be caused by clot migration from an aneurysmal cavity, an ischemic event should raise awareness of potential cerebral artery occlusion.