腫瘍により頚部回旋時に頚髄が慢性・間欠的に圧迫され脊髄症を呈した1例

Cervical Myelopathy Caused by Chronic and Intermittent Cord Compression by Tumors upon Neck Rotation:A Case Report

Ⅰ．はじめに

　頚椎の動きは他部位の脊椎よりも自由度が高いため，頚椎症をはじめとした頚部脊椎・脊髄疾患は，病変による静的なmass effectだけでなく，動的要素の影響を受けやすい特殊性がある．今回，神経線維腫症1型（neurofibromatosis type 1：NF1）患者において，C1-2の硬膜内外に発生した神経線維腫が，頚部回旋により頚髄を圧迫して脊髄症を呈した症例を経験した．腫瘍あるいは周囲の異常構造物が，頚部の回旋運動により頚髄を圧迫するという報告は現在まで3報告4症例しかなく^1-3)，稀ではあるが注目すべき病態と考えられ，報告する．

　A 35-year-old man with neurofibromatosis type Ⅰ presented with right arm weakness and gait disturbance that had developed gradually. MR imaging revealed bilateral intra-and extradural tumors at the C1-2 level. Although the adjacent spinal cord was narrowed, there was no evident contact between the tumors and the spinal cord. Computed tomography myelography revealed that the tumors compressed the cord only during neck rotation. The tumors were resected to make an abundant subdural space around the affected cord. The patient's neurological symptoms improved postoperatively. Because contact between the masses and spinal cord only occurred upon neck rotation, we believe it is important to consider the possibility of intermittent compression, termed dynamic rotational canal stenosis, in patients with masses at the C1-2 level, even when such masses are not seen to be in contact with the cervical cord on routine radiological examination.