Hemorrhagic events associated with unfused or twig-like configuration of the Middle cerebral artery: A rare vascular anomaly with clinical relevance

Abstract

Introduction Twig-like middle cerebral artery configuration (Tw-MCA) is a rare and commonly misdiagnosed vascular anomaly characterized by a plexiform arterial network that replaces the normal M1 segment. The prevalence and clinical relevance of this anomaly is not fully established. Material and methods We sought to explore the prevalence of Tw-MCA in patients clinically referred to digital angiography in a single academic comprehensive endovascular center and evaluated the radiological and clinical findings among patients with hemorrhagic events. Results From 2011 to 2020, a total of 10,234 patients underwent a cerebral angiography at our institution. During this period, 9 (0.088%) Tw-MCAs were identified. Out of these, 5 patients (62.5%) were admitted due to an intracranial hemorrhage. Two patients had a ruptured intracranial aneurysm on the anterior communicating artery, one with multiple brain aneurysms; two patients presented an intraparenchymal hematoma (IPH) due to the presence of a periventricular anastomosis and one patient an intraventricular hemorrhage with unclear origin. Conclusion Tw-MCA is a very rare vascular anomaly associated with hemorrhagic events. Adequate identification of this anomaly is essential in order to avoid misdiagnosis as steno-occlusive disorders.