title: Dissecting aneurysms at the A1 segment of the anterior cerebral artery--two case reports.
abstract: Two rare cases of dissections which involve the anterior cerebral artery (ACA) are reported. A 58-year-old woman presented with a ruptured dissecting aneurysm manifesting as sudden onset of severe headache and consciousness disturbance followed by aphasia, right hemiparesis, paresis of the left lower extremity, and choreoathetotic movements of the upper arms and face. Computed tomography and angiography revealed subarachnoid hemorrhage due to a dissecting aneurysm at the left A1 segment. The dissecting aneurysm was trapped surgically on the day of onset. Her neurological deficits disappeared within a month. A 39-year-old woman experienced continuous dull headache from the day before onset, and then suffered right hemiparesis. Magnetic resonance (MR) imaging revealed cerebral infarction at the left globus pallidus. Angiography and MR imaging revealed a dissecting aneurysm at the left A1 segment and occlusion of the left Heubner's artery. She received conservative treatment and her neurological findings were improved. Dissections or dissecting aneurysms involving the ACA can be classified into three types: Extension of a dissection to the ACA from the internal carotid artery, dissection at the A1 segment, and dissection at the A2-A4 segments. These types of dissection have distinct uniform clinical features.
authors.affiliation: Department of Neurosurgery, Institute of Neurological Sciences, Tottori University School of Medicine, Yonago, Tottori.
authors.forename: J
authors.initials: J
authors.lastname: Hirao
authors.forename: H
authors.initials: H
authors.lastname: Okamoto
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
authors.forename: S
authors.initials: S
authors.lastname: Asano
authors.forename: A
authors.initials: A
authors.lastname: Teraoka
mesh_terms: D000784:Aortic Dissection / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D017542:Aneurysm, Ruptured / Q000150:complications / Q000175:diagnosis / Q000601:surgery; D020771:Anterior Cerebral Artery / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D002533:Cerebral Angiography; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D014057:Tomography, X-Ray Computed