Department of Neurology, Mayo Clinic, Rochester, Minnesota.
Department of Neurology, Auckland City Hospital, Auckland, New Zealand.
Muscle Nerve. 2019 Dec;60(6):648-657. doi: 10.1002/mus.26676. Epub 2019 Sep 10.
Although myopathies and neuromuscular junction disorders are typically distinct, their coexistence has been reported in several inherited and acquired conditions. Affected individuals have variable clinical phenotypes but typically display both a decrement on repetitive nerve stimulation and myopathic findings on muscle biopsy. Inherited causes include myopathies related to mutations in BIN1, DES, DNM2, GMPPB, MTM1, or PLEC and congenital myasthenic syndromes due to mutations in ALG2, ALG14, COL13A1, DOK7, DPAGT1, or GFPT1. Additionally, a decrement due to muscle fiber inexcitability is observed in certain myotonic disorders. The identification of a defect of neuromuscular transmission in an inherited myopathy may assist in establishing a molecular diagnosis and in selecting patients who would benefit from pharmacological correction of this defect. Acquired cases meanwhile stem from the co-occurrence of myasthenia gravis or Lambert-Eaton myasthenic syndrome with an immune-mediated myopathy, which may be due to paraneoplastic disorders or exposure to immune checkpoint inhibitors.
虽然肌病和神经肌肉接头疾病通常是不同的，但它们在几种遗传性和获得性疾病中同时存在已有报道。受影响的个体具有不同的临床表型，但通常同时表现为重复神经刺激的衰减和肌肉活检的肌病发现。遗传性病因包括与 BIN1、DES、DNM2、GMPPB、MTM1 或 PLEC 基因突变相关的肌病，以及由于 ALG2、ALG14、COL13A1、DOK7、DPAGT1 或 GFPT1 基因突变导致的先天性肌无力综合征。此外，在某些肌强直性疾病中也观察到由于肌肉纤维不应激导致的衰减。在遗传性肌病中发现神经肌肉传递缺陷可能有助于建立分子诊断，并选择受益于该缺陷药物矫正的患者。同时，获得性病例源于重症肌无力或 Lambert-Eaton 肌无力综合征与免疫介导性肌病同时发生，这可能是由于副肿瘤性疾病或免疫检查点抑制剂暴露所致。
