くも膜下出血で発症した上部頸髄硬膜動静脈瘻（spinal dural AVF）

A Rare Case of High Cervical Spinal Cord Dural Arteriovenous Fistula Presenting with Intracranial Subarachnoid Hemorrhage

I．はじめに

　最近国内脳神経外科領域において脊髄動静脈奇形（AVM）に遭遇する機会が増加して来た．これに伴い国内外のこの疾患に対する臨床的研究報告の数も増して来た．従来DiChiroら^3,4）の分類したsingle coil vesselAVMは実はdural AVMが大半で，唐澤ら^7,8）や宮本ら^9）の分類ではradiculomeningeal AVM（AV Fistel）に分けられている．

　脊髄のdural AVMはarteriovenous fistula（AVF）とも呼ばれ呼称に統一はない．一般にspinal dural AVFはcongestive venous hypertensionによるmyelopathyが症状発現に関与すると考えられる．最近私共はくも膜下出血（SAH）にて来院，その原因がhigh cervical spin—al AVMと診断された症例に対し外科的手術を施行した．手術の結果dural typeのAVFであり，出血源は硬膜内varix部のblebであった．

It is now recognized that spinal dural arteriovenous fistula causes myelopathy, resulting from congestive venous hypertension of the spinal cord. We have re-cently encountered a rare case of high cervical spinal cord dural arteriovenous fistula which caused intracra-nial subarachnoid hemorrhage.

The patient was a 62-year-old female, who had exhi-bited an abrupt onset of severe headache and loss of consciousness. Plain head CT scan revealed intracranial subarachnoid hemorrhage. No abnormal vascular le-sions were found on the first cerebral angiography. The second angiographical examination demonstrated a spinal arteriovenous malformation at the high cervical region.

A dural arteriovenous fistula around the right C₂ nerve root was found by surgical intervention. The fis-tula was recognized between rt. C₂ radicular artery and dural sheath of rt. C₂ nerve root, draining to the epidu-ral plexus and intradural local medullary vein. No ser-pentine coronal venous plexus on the dorsal aspect of the cervical cord was seen as it is in a usual dural type of spinal arteriovenous fistula. The bleeding point was an intradural varix of the medullary vein just where it penetrated the nerve root area. Feeder ligation of the C₂ radicular artery and coating of the varix complex were performed.

The postoperative course was uneventful. The pa-tient was discharged from our institute with no neuro-logical deficits.