神経痛性筋萎縮症

Neuralgic Amyotrophy

神経痛性筋萎縮症は片側上肢の神経痛で発症し，疼痛の軽快後に肩甲上腕部を中心とした限局性筋萎縮を生じる疾患である。腕神経叢上部とその近傍を首座とする特発性末梢神経障害と考えられており，感染や外傷，労作，遺伝性素因などの誘因が知られる。典型例のほかに，遠位筋優位例や前骨間・後骨間神経麻痺，腰仙神経叢障害など，多様な臨床亜型が知られる。運動機能予後は必ずしも良好ではないが，治療法は確立されていない。

Abstract

Neuralgic amyotrophy (NA) is a distinct peripheral nervous system (PNS) disorder characterized by sudden attacks of neuropathic pain, usually in a unilateral upper extremity, and patchy paresis with atrophy in the glenohumeral muscles. The lesion sites of NA are commonly considered to be upper brachial plexus (BP) and/or individual branches of the BP. The cause of NA remains unknown. Some evidence suggests a complex pathogenesis in NA that includes predisposition and susceptible PNS structures, and it can be triggered by infection, trauma, and strenuous exercise. NA is considered to be broad and encompasses a spectrum of atypical presentations, including involvement of the lower part of the BP, isolated nerves (anterior interosseous nerve or posterior interosseous nerve), or lumbosacral plexuses. Functional prognosis of NA is less favorable than previously assumed; however, specific therapy for patients with NA remains to be established.