くも膜下出血にて発症した脊髄動静脈奇形の2例

Two Cases of Spinal Arteriovenous Malformation Presenting with Subarachnoid Hemorrhage

　Ⅰ．はじめに

脊髄動静脈奇形は比較的稀な疾患で，血流シャントの解剖学的見地よりintramedullary arteriovenous malformation（AVM），perimedullary AVM/arteriovenous fistula（AVF），dural AVFの3つに分けられる^5,9,15,16)．今回，われわれはくも膜下出血にて発症したintramedullary AVMとdural AVFの2例を経験した．症例を報告し，脊髄動静脈奇形からのくも膜下出血の特徴について考察する．

　Two cases of spinal arteriovenous malformation (AVM) with subarachnoid hemorrhage (SAH) are reported. The first case is that of a 14-year-old boy who was transferred to our hospital with a sudden onset of headache. Neurological examination revealed no motosensory deficit,but a brain CT showed a slight diffuse SAH. A left vertebral angiogram demonstrated intramedullary AVM in the cervical region of the spinal cord. This AVM was therefore occluded using a solid embolization material. The patient was then discharged without neurological deficit. The second case is that of a 67-year-old man who visited our hospital with a sudden onset of headache. Neurological examination revealed no motor or sensory deficit,but a brain CT showed SAH,which was dominant in the posterior fossa. Initial cerebral angiography demonstrated no abnormality such as cerebral aneurysm or AVM except for laterality of the C1 radiculo-meningeal artery. A second angiogram on day 11 demonstrated spinal arteriovenous fistula (AVF),which was fed by the left radiculo-meningeal artery and drained to the posterior spinal vein. Embolization for the AVF was performed using liquid material. He was then discharged without neurological deficit. These two cases revealed non-specific SAH symptoms and were indistinguishable from other ruptured aneurysms. Although the brain CT can show a slight SAH or posterior fossa dominant SAH,repeated angiography may be necessary to verify and conclude the diagnosis of spinal AVM.