Anterior choroidal artery supply to the posterior cerebral artery distribution: Embryological basis and clinical implications

OBJECTIVE AND IMPORTANCE: We report four cases of anomalous anterior choroi dal artery supply to the temporal, parietal, and occipital cortical regions normally supplied by branches of the posterior cerebral artery. Three of t hese cases were associated with significant intracranial vascular pathology . We examine the embryological basis for the anomalous vascular anatomy to emphasize the potential variability of the anterior choroidal artery distri bution and illustrate the spectrum of this variability angiographically. Th ese variants may also have significant implications for surgical and endova scular treatment. CLINICAL PRESENTATION: One patient was diagnosed with an arteriovenous malf ormation, and two patients were diagnosed with aneurysms, one of which pres ented with a subarachnoid hemorrhage. INTERVENTION: The patient with the arteriovenous malformation underwent pre operative embolization and surgical resection, one patient with an aneurysm was treated via surgical clipping, and the other aneurysm underwent endova scular coiling. CONCLUSION: This group of patients illustrates an underemphasized but poten tially important vascular anomaly. Phylogeny and embryology of the intracer ebral vessels suggest a mechanism related to transposed distributions. Care ful attention must be directed to the microvascular anatomy of the intracer ebral circulation so that these anomalies are recognized and, if necessary, factored into surgical and interventional planning.