摘要： 重症肌无力患者可见自主神经症状和使用药物后肌无力症状的加重。自主神经症状可能为重症肌无力临床表现的一部分，亦可由伴随疾病所致；药物引起的肌无力症状加重可能是药物直接作用于神经肌肉接头处，亦可能与其他机制有关。明确事件之间的相伴、相关和因果关系，不仅有利于认识疾病的机制，还能更好地解决临床问题。

关键词: 重症肌无力, 因果律, 综述

Abstract: Symptoms of autonomic nervous system involvement and exacerbation of weakness after taking several medicines are often seen in myasthenia gravis (MG). The autonomic nervous system involvement may be a part of clinical manifestation of MG or may be caused by concomitant diseases in MG. The exacerbation of weakness may be direct effects of medicine on neuromuscular junction or complex impact resulting from various mechanisms. To elucidate the concurrence, association or causal relationship between events not only helps to explore the mechanism of diseases, but also to solve the clinical problems.

Key words: Myasthenia gravis, Causality, Review