Objective Detect the occurrence and characteristics of A-waves in amyotrophic lateral sclerosis (ALS) and demyelinating neuropathies (DN). Methodology Nerve conduction studies (NCS) of 28 patients (14 patients with ALS and 14 patients with DN) were reanalyzed to look for A-waves. Results We studied 61 nerves of the ALS group and 64 nerves of DN. In the ALS group, A-waves were detected in 21 nerves out of 61 nerves (34.4%). In the DN group, A-waves were recorded from 25 nerves out of 64 nerves (39%). In the DN group, A-waves were detected more often in nerves of upper extremities than lower extremities (out of a total of 25 nerves with A-waves, 18 median and ulnar nerves showed A-waves (72%) and that was statistically significant ( P = 0.0021)). Complex A-waves (CAWs) occurred exclusively in patients with DN. Conclusion Most of the A-waves in the DN group were recorded more frequently from nerves of the upper extremities than those from lower extremities. CAWs occurred only in DN. Significance CAW seems to be a useful specific electrodiagnostic tool to distinguish DN from ALS.

中文翻译：

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肌萎缩侧索硬化 (ALS) 与脱髓鞘性神经病 (DN) 患者的 A 波特征

目的检测肌萎缩侧索硬化（ALS）和脱髓鞘性神经病（DN）A波的发生及特点。方法学 对 28 名患者（14 名 ALS 患者和 14 名 DN 患者）的神经传导研究 (NCS) 进行了重新分析以寻找 A 波。结果我们研究了ALS组的61条神经和DN的64条神经。在 ALS 组中，在 61 条神经中的 21 条（34.4%）中检测到 A 波。在 DN 组中，从 64 条神经中的 25 条（39%）记录到 A 波。在 DN 组中，在上肢神经中检测到 A 波的频率高于下肢（在共有 25 条有 A 波的神经中，有 18 条正中和尺神经显示 A 波（72%），这是统计学上的显着（P = 0.0021））。复杂 A 波 (CAW) 仅发生在 DN 患者中。结论 DN组A波多为上肢神经记录，多于下肢神经记录。CAW 仅发生在 DN。意义 CAW 似乎是区分 DN 和 ALS 的一种有用的特定电诊断工具。