The early diagnosis of amyotrophic lateral sclerosis (ALS) is often difficult as not all patients meet clinical and electrophysiological criteria.1 Additionally a small per cent of patients have a divergent diagnosis, most commonly multifocal motor neuropathy (MMN) or motor-predominant multifocal acquired demyelinating sensory and motor neuropathy (MADSAM).2 Although motor conduction blocks distinguish MMN and MADSAM from ALS, it is often difficult to find these conduction abnormalities when present at the roots or plexus. Currently biomarkers to assist in the diagnosis of ALS versus MMN and MADSAM are inadequate. Specifically, GM1 (ganglioside monosialo-asialo) autoantibodies can be present in all these disorders, although typically of lower values in ALS. Recently, IgM-gammopathy was suggested to be more common in MMN (7%) compared with healthy (2%) and ALS (1%) controls.3 If true, IgM-gammopathy may forebode for an immune treatment refractory disorder as described in other IgM-gammopathy neuropathies.4 Herein, we address: (1) the occurrence of an IgM-gammopathy in MMN and MADSAM compared with ALS and (2) evaluate the immune treatment response of MMN and MADSAM IgM-monoclonal-gammopathy. ### Clinical characteristics We identified 78 MADSAM, 65 MMN cases and 412 ALS patients matched in gender and age. ALS was considered in the differential diagnosis of 51% (40/78) of MADSAM and 64% (42/65) of MMN patients due to motor predominant progressive symptoms. IgM-gammopathy was significantly (p<0.001; OR estimate of 33, 95% CI) more common in MADSAM 23% (18/78) and MMN 17% (11/65) compared with ALS<1% (2/412) (figure 1). IgM-Kappa was the most …

中文翻译：

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与ALS相比，IgM变性病强烈支持可免疫治疗的MMN和MADSAM。

肌萎缩性侧索硬化症（ALS）的早期诊断通常很困难，因为并非所有患者都符合临床和电生理标准。1此外，一小部分患者的诊断有所不同，最常见的是多灶性运动神经病（MMN）或以运动为主的多灶性获得性脱髓鞘的感觉和运动神经病（MADSAM）。2尽管运动传导阻滞使MMN和MADSAM与ALS区别开来，但当在根或丛中出现时，通常很难发现这些传导异常。目前，用于协助诊断ALS与MMN和MADSAM的生物标志物不足。具体而言，GM1（神经节苷脂单唾液酸-亚洲）自身抗体可以存在于所有这些疾病中，尽管在ALS中通常值较低。最近，与健康对照者（2％）和ALS对照者（1％）相比，MMG（7％）中IgM球菌病更常见。3如果为真，IgM球菌病可能因其他IgM中所述的免疫治疗难治性疾病而退步-gammopathy神经病。4在此，我们解决：（1）与ALS相比，MMN和MADSAM中存在IgM-γ病；（2）评价MMN和MADSAM IgM-单克隆-γ病的免疫治疗反应。###临床特征我们确定了78例MADSAM，65例MMN病例和412例ALS患者，其性别和年龄相匹配。由于运动为主的进行性症状，在鉴别诊断MADSAM的51％（40/78）和MMN患者的64％（42/65）时考虑了ALS。与ALS <相比，MADSAM 23％（18/78）和MMN 17％（11/65）的IgM球蛋白病显着（p <0.001； OR估计为33，95％CI）更为常见。1％（2/412）（图1）。IgM-Kappa最多...