We propose the finger drop sign as a new clinical variant of acute motor axonal neuropathy (AMAN) defined by immunological and radiological evidence. We identified eight consecutive patients who had AMAN. All of them developed prominent involvement of the finger extensors. We performed magnetic resonance imaging (MRI) of the extremity muscles and serological assays for antiganglioside antibodies and Campylobacter jejuni. Patients with AMAN showed characteristic and a markedly sustained weakness of the finger extensors with a distinctive pattern of the finger drop sign. Limb MRI revealed unevenly distributed abnormal signals in the muscles mainly innervated by the posterior interosseous nerve. All tested patients showed positivity for immunoglobulin G antibody against ganglioside complex of GM1 and phosphatidic acid. A pathophysiological understanding of this unique syndrome can provide further insight into antiganglioside‐antibody‐mediated axonal injury in Guillain‐Barré syndrome.

中文翻译：

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手指掉落征作为急性运动性轴索神经病的新变种

我们提出手指掉落迹象是由免疫学和放射学证据定义的急性运动轴突神经病（AMAN）的一种新的临床变体。我们确定了八名患有AMAN的连续患者。他们都发展出手指伸肌的突出表现。我们进行了四肢肌肉的磁共振成像（MRI）以及抗神经节苷脂抗体和空肠弯曲菌的血清学检测。AMAN患者表现出手指伸肌的特征性和明显持续的虚弱，并伴有明显的手指掉落迹象。肢体MRI显示主要在后骨间神经支配的肌肉中分布不均匀的异常信号。所有测试的患者均显示出针对GM1和磷脂酸的神经节苷脂复合物的免疫球蛋白G抗体呈阳性。对这种独特综合征的病理生理学了解可以为Guillain-Barré综合征中抗神经节苷脂抗体介导的轴突损伤提供进一步的见解。