頚部神経根症に対する斜角筋間ブロックの除痛効果と頚椎に由来した肩甲帯部痛と前胸部痛のメカニズムの検討

Interscalene Brachial Plexus Block for Pain due to Cervical Radiculopathy and the Pain Mechanism of Referred Scapular Pain and Upper Chest Pain

目的：頚椎由来の肩甲帯部や前胸部の痛み(関連痛)の伝達経路を調べることである．対象と方法：頚部神経根症患者に対し斜角筋間ブロック(以下IBPB)を行った．結果：神経根性の上肢の痛みは，IBPB5分後と7日後でIBPB前と比べ有意に低いvisual analogue scale(VAS)値を示した．関連痛は，星状神経節までブロックされていた患者のほうがブロックされていない患者より，IBPB5分後で有意に低いVAS値を示した．結語：関連痛の伝達経路は，交感神経幹を含むと考えられた．最も頭側に存在するT1やT2の白交通枝，およびT1やT2脊髄神経根が関連痛の経路と考えられた．

　Objectives：To study the pathway of scapula and upper chest pain (referred pain).　Materials and Methods：Patients who had cervical radicular pain and were treated with NSAIDs for at least 2 weeks were performed the interscalene brachial plexus block (IBPB).　The intensities of radicular and referred pain were measured using visual analog scale (VAS).　Results：The average VAS scores for radicular pain with or without referred pain were significantly reduced by the IBPB at 5 minutes and 7 days after the injection.　The referred pain was significantly reduced in the patients with stellate ganglion block (SGB) effect than those without SGB effect.　Conclusions：The referred pain pathway was likely interrupted by IBPB with the side effect of SGB.　The main afferent fibers of the cervical related pain pathway were thought to involve the T1 and/or T2 spinal nerve, presumably via sympathetic afferents.