Carotid–Anterior Cerebral Artery Anastomosis Associated with Paraclinoid Aneurysm and Ophthalmic Artery Originating From Middle Meningeal Artery: Case Report and Consideration of Terminology

BACKGROUND: We summarized 63 cases of anterior cerebral artery (ACA) anomaly with an infraoptic course reported in the literature including abstracts written in English. All cases were reported individually, with a maximum of 3 cases. This report describes our findings in another case and opinions regarding the terminology. CASE DESCRIPTION: A 78-year-old woman presented with subarachnoid hemorrhage. A carotid angiogram showed a right paraclinoid aneurysm with an anomaly of the ACA. The right ACA originated from the internal carotid artery at the level of the ophthalmic segment intradurally with an infraoptic course. The right ophthalmic artery originated from the ipsilateral middle meningeal artery. We performed an emergent endovascular coil embolization with balloon assistance, and the patient recovered well. CONCLUSIONS: Use of the terminology "infraoptic course of the ACA" versus "carotid-ACA anastomosis" was discussed. Based on the literature reports, at least one third of the cases have a normal-positioned ACA rather than the infraoptic ACA. Also, based on embryogenesis, it is thought that the infraoptic ACA is not a misplaced A1 segment, but rather persistence of an embryologic vessel. Therefore, based on the literature and embryology, we prefer the term "carotid-ACA anastomosis" rather than "infraoptic ACA." However, as a morphologic and positional description, the term "infraoptic ACA" has value. To the best of our knowledge, the present case of a carotid-ACA anastomosis associated with a paraclinoid aneurysm and ophthalmic artery originating from the middle meningeal artery is the first to appear in the literature.