神経根症状で発症した特発性椎骨動静脈瘻の1例

Spontaneous Vertebral Arteriovenous Fistula Manifestating as Radiculopathy

Ⅰ．はじめに

　椎骨動静脈瘻は頭蓋外の椎骨動脈，またはその分枝とそれに近接する静脈との異常な交通を本態とする稀な疾患である．症状は一般に拍動性の耳鳴（血管雑音），頚部痛，盗血流現象によるめまいなどが挙げられるが，拡張した静脈の圧迫による神経根症状や脊髄症状も報告^3,8,24)されている．椎骨動静脈瘻の病因としては外傷性，医原性の報告²⁴⁾のほかに，特発性として神経線維腫症1型や線維筋異形成症，Ehlers-Danlos症候群に伴うものが報告⁸⁾されている．今回われわれは，左上肢の神経根症状で発症した特発性の椎骨動静脈瘻の1例を経験したので，その文献的考察を加えて報告する．

　A 61-year-old man presented with a rare case of spontaneous vertebral arteriovenous fistula manifesting as radiculopathy of the left arm. MRI demonstrated an abnormal dilated vascular space on the left ventral aspect of the spinal canal and compression of the spinal cord and subarachnoid space. MRA disclosed a single high-flow vertebral arteriovenous fistula. Angiography showed a direct high-flow fistula at the C2-3 level between the left vertebral artery and the spinal extradural veinous plexus,and an abnormal dilated left vertebral artery with “string of beads”-like feature. The fistula was successfully obliterated by coil embolization with preservation of patency of the left vertebral artery,resulting in improvement of the signs and symptoms. Retrospectively this spontaneous vertebral arteriovenous fistula was considered in association with fibromuscular dysplasia.