Neurological Surgery 脳神経外科36巻3号

2008年03月発行

総説

術中運動誘発電位モニタリング

著者： 藤木稔¹

所属機関： ¹大分大学医学部脳神経外科学

ページ範囲：P.199 - P.204

Ⅰ．はじめに

　運動誘発電位（motor evoked potential；MEP）は，脳神経外科領域における運動機能の術中モニタリングとして有用である^{8,9,13,17,18,20,21)}．

　本法は，刺激・記録および麻酔法の改良により，その方法論ならびに所見の解釈が多様化しつつある．

　運動野の刺激方法は，脳表を直接電気刺激する方法¹²⁾に加え経頭蓋的に電気刺激する方法¹¹⁾が普及し，MEPの方法論に多様性を与えた．一方で，経頭蓋的な電気刺激により被刺激部位はより深くなるとされるが，その点については未だ議論の残るところである．MEPには脊髄硬膜外から記録するcorticospinal MEPと，末梢筋から記録するcorticomuscular MEPとがある．Katayamaらにより確立されたcorticospinal MEPは術中評価結果の定量性と術後運動機能との相関に優れる^8,19)．近年は麻酔方法の進歩も手伝い，より簡便なcorticomuscular あるいはmuscle MEPが術中に多用されるようになった^{7,9,13,17,18)}．しかし，後者の臨床的なcritical borderは未だ明確に示されていない．

　本総説は，MEPの理論的背景，麻酔・刺激・記録に関する方法論，結果の解釈と問題点を概説し，脳腫瘍外科で欠くべからざる手法となりつつある本法の今後の展望についても考察する．

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