ケタミン注入療法の著効した脊髄・脊椎領域における難治性疼痛の2症例

Ketamine Infusion Therapy for Refractory Neuralgia in Spinal Disease : report of two cases

I．はじめに

　ペインクリニックの領域において，近年ではN-methyl-D-aspartate受容体拮抗薬であるケタミンの神経因性の難治性疼痛に対する有効性が認識され始めている．今回われわれは，非ステロイド性抗炎症薬（NSAIDs）の内服や局所神経ブロックが無効あるいは効果不十分であった脊髄・脊椎領域疾患の2症例を経験し，これらの難治性疼痛に対してケタミン注入療法を施行したところ著効をみた．これらの症例について疼痛の病態およびケタミンの作用機序について考察し報告する．

We report two cases of refractory pain in a spinal disease. One case was a 60-year-old male who pre-sented intractable pain in bilateral upper extremities after anterior fusion (C5/6,6/7) for cervical spondylo-sis. The other was a 63-year-old female who also had intractable pain in the left anterio-lateral chest wallwith no remarkable past history. Both cases were refractory to nonsteroidal anti-inflammatory drugs(NSAIDs) or minor tranquilizer or local anesthesia with bupivacaine. However, their pain was significantlyrelieved by the intravenous administration of a test close (5mg) of ketamine which is a noncompetitiveblocker of N-methyl-D-aspartate (NMDA) receptors.

As for case 1, the effect of the injection of the test dose lasted, so continuing infusion therapy of keta-mine was cancelled. In case 2, recurrence of the pain was recognized gradually. She underwent continuinginfusion therapy of 2mg/kg of ketamine, and it brought about continued pain relief.

We conclude that ketamine infusion therapy should also he considered for therapy of refractory neural-gia in spinal disease.