title: A saccular-like dissecting aneurysm of the anterior cerebral artery that developed 2 years after an ischemic event.
abstract: BACKGROUND
  A rare case of a growing dissecting aneurysm, which was located at the horizontal (A1) segment of the anterior cerebral artery (ACA), is reported.
  
  
  METHODS
  A 53-year-old woman experienced left hemiparesis and alien hand syndrome. A computerized tomography scan showed an infarction in the right frontal lobe, and cerebral angiography revealed a false lumen and intimal flap at the A1 segment of the ACA. Magnetic resonance angiography demonstrated that the stenosis progressed 6 months later and improved 1 year later. Cerebral angiography showed a saccular-like aneurysm 2 years later. The surgery was planned for prevention of aneurysmal rupture. The aneurysm, which was cocoon shaped, was exposed surgically and was resected. Histological examination of the aneurysm showed arterial dissection. The postoperative course was uneventful without additional neurological deficits.
  
  
  CONCLUSIONS
  This is the first case report of A1 dissecting aneurysm presenting with an ischemic event in the literature. The sequential change of the configuration was curious to develop aneurysmal dilatation in 2 years. Long-term follow-up is necessary even after disappearance of the arterial dissection.
authors.affiliation: Department of Emergency and Intensive Care Medicine, Shinshu University School of Medicine, Matsumoto 390-8621, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Iwashita
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kitazawa
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Koyama
authors.forename: Hisashi
authors.initials: H
authors.lastname: Nagashima
authors.forename: Toru
authors.initials: T
authors.lastname: Koyama
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Hongo
mesh_terms: D000784:Aortic Dissection / Q000209:etiology* / Q000601:surgery*; D020771:Anterior Cerebral Artery / Q000473:pathology*; D002545:Brain Ischemia / Q000150:complications*; D002533:Cerebral Angiography; D005260:Female; D006801:Humans; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D010291:Paresis / Q000209:etiology; D013997:Time Factors; D016896:Treatment Outcome