title: Progressive perianeurysmal edema preceding the rupture of a small basilar artery aneurysm.
abstract: We herein report the first case of progressive perianeurysmal edema preceding the rupture of a small saccular aneurysm, without any intervention or intraluminal thrombosis. A 71-year-old woman was incidentally noted to have a cerebral aneurysm (5mm in diameter) at the lower basilar artery. Twelve months later, magnetic resonance (MR) imaging showed a T2-elongated area around a dome of the aneurysm buried in the brain stem, suggesting perianeurysmal edema formation. Interestingly, the edema progressed with the formation of a bleb, in addition to an increase in size of the aneurysm over the following 3-year period. The aneurysm eventually ruptured as a brain stem hemorrhage without any subarachnoid clots 3 days after the final check-up with MR imaging, by which a significant increase of edema formation with an increase in size of the aneurysm and a marked expansion of the bleb was observed. These findings raise the possibility that bleb formation and an enlargement of a small cerebral aneurysm might also be associated with perianeurysmal edema and a subsequent aneurysmal rupture. In addition to the pulsatile flow and/or compression from the expanded aneurysm, local inflammation in the aneurysm wall may play an important role in such edema formation.
authors.affiliation: Department of Neurosurgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan. thiu-nagasaki@umin.ac.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hiu
authors.forename: Keisuke
authors.initials: K
authors.lastname: Tsutsumi
authors.forename: Naoki
authors.initials: N
authors.lastname: Kitagawa
authors.forename: Kentaro
authors.initials: K
authors.lastname: Hayashi
authors.forename: Kenta
authors.initials: K
authors.lastname: Ujifuku
authors.forename: Akio
authors.initials: A
authors.lastname: Yasunaga
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Suyama
authors.forename: Izumi
authors.initials: I
authors.lastname: Nagata
mesh_terms: D000368:Aged; D017542:Aneurysm, Ruptured / Q000175:diagnosis* / Q000209:etiology; D001488:Basilar Artery / Q000000981:diagnostic imaging; D001929:Brain Edema / Q000150:complications* / Q000473:pathology; D002533:Cerebral Angiography; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000175:diagnosis* / Q000209:etiology; D008279:Magnetic Resonance Imaging; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed