反対側にのみ下肢症状を呈した腰椎椎間板ヘルニアの2例

Lumbar Disc Herniation Manifested by Contralateral Symptoms Alone. Case Report

　症例1は50歳の男性で，主訴は右大腿前面痛と右下肢筋力低下であったが，MRIでは左L1/2椎間板ヘルニアを認めた．術中所見では，ヘルニアによる硬膜管の右後方への圧排と右L2神経根の周辺組織との癒着を認めた．術後，症状は軽快した．

　症例2は55歳の男性で，主訴は左大腿前面疼痛であったが，MRIでは右L2/3椎間板ヘルニアを認めた．保存的治療で症状は軽快した．

　本症例では症状側の神経根に癒着を認めたことから，神経根にfriction neuritisが存在したと考えられた．このことから本病態は，神経根のfriction neuritisにより易刺激性が高まり，反対側からの軽度な圧迫でも症状が出現したと考えられた．

　Case 1：A 50-year-old man experienced pain and weakness in his right leg. Radiculopathy on the right side was suspected, but MRI revealed disc herniation on the left side at the L1/2 level. Fenestration at L1/2 and discectomy was performed. Intraoperatively, the dura was observed to have been displaces to the right and posteriorly by the herniation, and there were right L2 nerve root adhesions. All of the patient's symptoms improved postoperatively.

　Case 2：A 55-year-old man experienced pain in his left legs. Radiculopathy on the left side was suspected, but MRI revealed disc herniation at the L2/3 level on the right side. Conservative treatment was successful, and all of the patient's symptoms improved.

　In both cases there was adhesion of the nerve root symptomatic side, and friction neuritis of the nerve root was assumed to have developed. Thus, the cause of lumbar disc herniation manifested by contralateral symptoms alone is for irritability by friction neuritis.