[Two cases of spinal arteriovenous malformation presenting with subarachnoid hemorrhage].

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.