高齢者特発性脊髄ヘルニアの1症例

A Case of High-aged Idiopathic Spinal Cord Herniation from Dural Defect

Ⅰ．は じ め に

　特発性脊髄ヘルニアは，進行性の脊髄障害を呈する疾患で，以前は稀な疾患であるとされていた．しかし，近年ではmagnetic resonance imaging（MRI），computed tomography myelogram（CTM）などの画像診断の急速な進歩により，本疾患の概念や病態が周知されるようになり，徐々に日常臨床での報告例が増加しつつある^4,10)．したがって，特発性脊髄ヘルニアは，胸髄髄節に感覚障害レベルを有するparaparesis例やBrown-Séquard症候群例の鑑別診断として，念頭に置くべき疾患の1つとなっている．今回，われわれは硬膜欠損部より脊髄が右腹側に突出した高齢者特発性脊髄ヘルニアの1例を経験したので，若干の文献的考察を加えて報告する．

Idiopathic spinal cord herniation was assumed to be a rare disease. However,the incidence of discovering this condition appears to have been increasing recently with advances in neuroradiological diagnosis using magnetic resonance imaging (MRI) and computed tomographic myelogram (CTM). We present herein an operated case of high-aged idiopathic spinal cord herniation. A 71-year-old female presented with spastic paresis of the right lower limb and sensory disturbance of pain and temperature below the level of the left Th4 dermatome,consistent with Brown-Séquard syndrome. MRI and CTM revealed right ventral displacement of the spinal cord and dilatation of the dorsal subarachnoid space at Th2/3. Laminectomy of Th1-3 was performed,herniated spinal cord was untethered and repositioned,and the dural defect was sealed with GORE-TEX^(R) dura substitute. Postoperative MRI revealed normal location of the spinal cord and neurological state improved slightly. The patient was discharged 1 month after the operation.

　Among many cases of spinal cord herniations,this is considered to be a rare case of idiopathic spinal cord herniation in an elderly patient.