Inflammatory myopathies: an update for neurologists

ABSTRACT Idiopathic inflammatory myopathies (IIM) are a heterogenous group of treatable myopathies. Patients present mainly to the rheumatologist and neurologists, complaining of acute or subacute onset of proximal weakness. Extramuscular manifestations may occur, including involvement of the lungs, skin, and joints. Classically, the diagnosis used to be made based on the creatine kinase level increase, abnormalities in electroneuromyography and presence of inflammatory infiltrates in the muscle biopsy. Recently, the importance of autoantibodies has increased, and now they may be identified in more than half of IIM patients. The continuous clinicoseropathological improvement in IIM knowledge has changed the way we see these patients and how we classify them. In the past, only polymyositis, dermatomyositis and inclusion body myopathy were described. Currently, immune-mediated necrotizing myopathy, overlap myositis and antisynthetase syndrome have been considered the most common forms of IIM in clinical practice, increasing the spectrum of classification. Patients previously considered to have polymyositis, in fact have these other forms of seropositive IIM. In this article, we reviewed the new concepts of classification, a practical way to make the diagnosis and how to plan the treatment of patients suffering from IIM.

摘要 特发性炎性肌病（Idiopathic inflammatory myopathies, IIM）是一组异质性可治疗肌病。患者多就诊于风湿科与神经科医师，主诉急性或亚急性起病的近端肌无力。本病可出现肌外表现，累及肺、皮肤与关节。既往经典诊断依据为肌酸激酶水平升高、神经肌电图（electroneuromyography）异常及肌肉活检见炎性浸润灶。近年来，自身抗体的诊断价值日益凸显，超过半数的IIM患者可检测到自身抗体。随着对IIM临床-血清学-病理维度认知的持续深化，我们对这类患者的认知与分类方式已发生改变。过去仅报道过多发性肌炎、皮肌炎与包涵体肌病。当前，免疫介导性坏死性肌病、重叠肌炎及抗合成酶综合征已成为临床实践中最常见的IIM亚型，拓展了IIM的分类谱系。既往被诊断为多发性肌炎的患者，实际上多属于这类血清学阳性的IIM。本文综述了IIM分类的新理念、实用化诊断路径及患者治疗方案的规划策略。