骨形成不全症に合併した破裂脳動脈瘤及び椎骨動脈窓形成の1例

A Case of Ruptured Cerebral Aneurysm associated with Fenestrated Vertebral Artery in Osteogenesis Imperfecta

I．はじめに

　Marfan症候群，Ehlers-Danlos症候群，弾性線維性仮性黄色腫などは，血管系の異常を高率に合併することが知られている．しかし，同じ遺伝性結合織疾患である骨形成不全症（osteogenesis imperfecta）では，その頻度は極めて少ないとされている^5）．特に脳血管系病変としてはモヤモヤ病^8）と頸動脈—海綿静脈洞（CCF）^1）が報告されているのみである．

　今回われわれは，骨形成不全症に破裂脳動脈瘤及び椎骨動脈窓形成を合併した症例を経験したので，若干の文献的考察を加え報告する．

An extremely rare case of ruptured cerebral aneu-rysm associated with a fenestrated vertebral artery in osteogenesis imperfecta (OI) is presented. A 33-year-old female suffering from OI was admitted to our hos-pital with severe headache and vomiting. A CT scan re-vealed subarachnoid hemorrhage. Cerebral angiography with four vessel study showed a fenestration in the V3portion of the left vertebral artery and a dilatation in its V4 portion, but no cerebral aneurysm was detected. Af-ter conservative treatment for three weeks, repeated angiography demonstrated an aneurysm of the anterior communicating artery. A neck clipping of the aneurysm was performed successfully. The patient was dis-charged with no neurological deficits. OI is a hereditary connective tissue disease characterized by bone fragil-ity. From her family history and clinical findings, the patient was suspected to have OI type I of Sillence's classification. Among the connective tissue diseases, OI does not have complications in the cerebrovascular sys-tem as frequently as other connective tissue diseases do, for example, Marfan's syndrome, Ehlers-Danlos syndrome, or pseudoxanthoma elasticum. Carotid-cavernous fistula and moyamoya disease have been the only complications reported in OI. However, dilatation of the aortic root and increased vascular fragility have been reported recently in OI. Although this is the first reported case of a ruptured aneurysm accompanied by a fenestration and a dilatation of the vertebral artery associated with OI, it was suggested that vascular fra-gility caused by collagen abnormality might affect the cerebral vasculature.