Twig-like middle cerebral artery or Moya Moya

Background. Several anomalies of the middle cerebral artery have been described in humans. Since the early 2000s, an anatomical variant called “twig-like middle cerebral artery” has been described. It is defined as the replacement of the M1 segment by a plexiform network of vessels. Pathophysiology, clinical and radiological modalities of detection and follow-up are still unclear, although it may have clinical consequences.Methods. We present two cases of patients with twig-like middle cerebral artery hospitalised in the neurovascular unit in Rennes - Pontchaillou University Hospital between July 2022 and February 2023. We then carried out a literature review of cases of twig-like MCA in order to better define the clinical and imaging characteristics of this disorder.Results. Bleeding complications are the most frequent, often related to the rupture of an aneurysm. Complications are treated according to the usual procedure for stroke and cerebral haemorrhage. This entity is often misdiagnosed as Moya-Moya disease.Conclusion. Twig-like MCA is an emerging diagnosis which can lead to ischemic and hemorrhagic complications. The etiological, therapeutic and follow-up management remains unclear and further longitudinal studies are needed to improve patients’ care.