Department of Neurology, Teikyo University School of Medicine, Tokyo, Japan.
Department of Neurology, Kitasato University School of Medicine, Sagamihara, Japan.
Muscle Nerve. 2022 Mar;65(3):311-316. doi: 10.1002/mus.27480. Epub 2022 Jan 8.
INTRODUCTION/AIMS: Various signs of selective involvement have been reported in amyotrophic lateral sclerosis (ALS). In this study, we describe two new signs, "weak shoulder" and "arm sparing" signs.
Subjects were retrospectively identified from our electrodiagnosis database. Medical Research Council scores of relevant muscles were evaluated. Weak shoulder was defined as the deltoid (Del) muscle being weaker than the biceps brachii (BB)/triceps brachii (TB) muscles; that is, Del was weaker than either or both of the muscles and no stronger than either. Arm sparing was defined as both Del and the first dorsal interosseous (FDI) being weaker than BB/TB. Sensitivities of these signs were compared with other signs of selective involvement. The specificities of these signs were investigated in patients with cervical spondylotic amyotrophy (CSA) and multifocal motor neuropathy (MMN).
We reviewed 130 patients with ALS, 64 patients with CSA, and 16 patients with MMN. The weak shoulder and the arm sparing signs were observed in 73% and 55% of patients with ALS, 44% and 2% of patients with CSA (93% and 0% of patients with proximal CSA), respectively, and no patients with MMN. The sensitivity of the weak shoulder was higher than with conventional signs, whereas that of the arm sparing sign showed no difference.
The weak shoulder sign was highly sensitive in ALS, and was specific when compared with MMN. The arm sparing sign was highly specific for ALS. These two new signs are promising as clinical clues in the diagnosis of ALS.
简介/目的：在肌萎缩侧索硬化症（ALS）中，已经报道了各种选择性受累的迹象。在这项研究中，我们描述了两个新的迹象，即“弱肩”和“臂保留”迹象。
从我们的电诊断数据库中回顾性地确定了受试者。评估了相关肌肉的医学研究委员会评分。弱肩定义为三角肌（Del）比肱二头肌（BB）/肱三头肌（TB）弱；即 Del 比任何一个或两个肌肉都弱，比任何一个肌肉都强。臂保留定义为 Del 和第一背侧骨间肌（FDI）均比 BB/TB 弱。与其他选择性受累迹象相比，比较了这些迹象的敏感性。在颈椎病性肌萎缩症（CSA）和多灶性运动神经病（MMN）患者中研究了这些迹象的特异性。
我们回顾了 130 例 ALS 患者、64 例 CSA 患者和 16 例 MMN 患者。在 ALS 患者中，73%和 55%观察到弱肩和臂保留迹象，在 CSA 患者中，44%和 2%（在近端 CSA 患者中为 93%和 0%）观察到弱肩和臂保留迹象，而在 MMN 患者中没有观察到这些迹象。弱肩的敏感性高于常规迹象，而臂保留迹象的敏感性没有差异。
弱肩征在 ALS 中高度敏感，与 MMN 相比具有特异性。臂保留征对 ALS 具有高度特异性。这两个新迹象有望成为 ALS 诊断的临床线索。
