title: Ruptured True Anterior Choroidal Artery Aneurysm in Cisternal Segment.
abstract: BACKGROUND
  Rupture of a true anterior choroidal artery (AChA) aneurysm in the cisternal segment is extremely rare, whereas cases of a distal AChA aneurysm associated with moyamoya disease are increasingly reported.
  
  
  METHODS
  A 58-year-old woman presented with a severe headache and vomiting. Computed tomography demonstrated a subarachnoid hemorrhage without intraventricular or intracerebral hemorrhaging. Cerebral angiogram findings revealed a proximal AChA aneurysm mimicking an internal carotid artery aneurysm at the origin of the AChA. Intraoperative findings demonstrated a ruptured aneurysm located on a bend of the proximal AChA in the carotid cistern. Neck clipping of the aneurysm with preservation of the AChA led to a good outcome.
  
  
  CONCLUSIONS
  A rare case of ruptured true AChA aneurysm in the cisternal segment, unrelated to moyamoya disease, is presented as a cause of subarachnoid hemorrhage.
authors.affiliation: Department of Neurosurgery, Higashiosaka City General Hospital, Osaka, Japan. Electronic address: hyokota0001@gmail.com.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yokota
authors.affiliation: Department of Neurosurgery, Higashiosaka City General Hospital, Osaka, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Noguchi
authors.affiliation: Department of Neurosurgery, Higashiosaka City General Hospital, Osaka, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yokoyama
mesh_terms: D017542:Aneurysm, Ruptured / Q000000981:diagnostic imaging / Q000209:etiology* / Q000601:surgery*; D002533:Cerebral Angiography / Q000379:methods; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000209:etiology* / Q000601:surgery*; D008875:Middle Aged; D011149:Pons / Q000098:blood supply / Q000000981:diagnostic imaging / Q000601:surgery; D013345:Subarachnoid Hemorrhage / Q000150:complications* / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome
keywords: Anterior choroidal artery aneurysm; Distal anterior choroidal artery aneurysm; Subarachnoid hemorrhage