title: Anomalous internal carotid anastomosis to contralateral anterior cerebral artery.
abstract: BACKGROUND
  Many anomalies and variants in vascular anatomy have been reported in relation to the anterior cerebral artery (ACA).
  
  
  METHODS
  We encountered an apparently novel anomaly in a 30-year-old man admitted for disturbance of consciousness following a traffic accident. Computed tomography revealed an acute subdural hematoma and subarachnoid hemorrhage.
  
  
  CONCLUSIONS
  No vascular abnormalities related to the hemorrhage were detected by conventional angiography, so we concluded that the bleeding was of traumatic origin. Anomalous origin of the ACA was disclosed incidentally, with both A1 segments arising from the right internal carotid artery; no normal A1 segment of the left ACA was visualized. We discuss possible bases for this anomalous origin.
authors.affiliation: Department of Neurosurgery and Critical Care Medicine, Nippon Medical School, Tokyo, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Murai
authors.forename: Yukio
authors.initials: Y
authors.lastname: Ikeda
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Sato
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Akira
authors.initials: A
authors.lastname: Teramoto
mesh_terms: D000063:Accidents, Traffic; D000328:Adult; D020771:Anterior Cerebral Artery / Q000002:abnormalities*; D001159:Arterio-Arterial Fistula / Q000151:congenital* / Q000473:pathology; D002533:Cerebral Angiography; D002539:Cerebral Arterial Diseases / Q000151:congenital* / Q000473:pathology; D006408:Hematoma, Subdural / Q000150:complications; D006801:Humans; D008297:Male; D020206:Subarachnoid Hemorrhage, Traumatic / Q000150:complications