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

Interv Neuroradiol. 2021 Apr;27(2):285-290. doi: 10.1177/1591019920970430. Epub 2020 Oct 29.

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.

Keywords: MCA anomalies; Twig-Like MCA; middle cerebral artery; unfused MCA.

MeSH terms

  • Aneurysm, Ruptured*
  • Cerebral Angiography
  • Hemorrhage
  • Humans
  • Intracranial Aneurysm* / diagnostic imaging
  • Middle Cerebral Artery / diagnostic imaging