ABSTRACT

Objective: In addition to the split hand sign, other split phenomena of different muscles also exist in amyotrophic lateral sclerosis (ALS). We analyzed the incidence of split phenomena in multiple antagonistic muscle groups in ALS patients and explored whether clinical factors affected their occurrence.

Methods: 618 ALS patients were included from a single ALS center. Muscle strength in upper and lower limbs was evaluated using the modified Medical Research Council (MRC) scoring system (range from 1 to 13). Split phenomena between different antagonistic muscle groups were summarized, and the correlations with clinical factors were analyzed.

Results: Split phenomena were detected in 22.3% antagonistic muscles for flexion and extension of the elbow, 11.9% for the wrist, 23.9% for fingers, 18.2% for the ankle, and 14.7% for toes. These manifestations were characterized by preferential wasting of the elbow, wrist, and finger extensor muscles compared with the flexor muscles, and the ankle and toe dorsiflexor muscles compared with the plantar flexor muscles. The presence of muscle wasting was more common when the muscle strength was stronger than a modified MRC grade 6. No definite correlation was found between split phenomena and clinical factors, including age-at-onset, gender, disease duration, the region of onset, and pyramidal tract damage.

Discussion: Split phenomena of antagonistic muscle groups widely exist in ALS patients. No definitive and consistent clinical factors were observed that affected the occurrence of these phenomena.

摘要

目的：肌萎缩侧索硬化症（ALS）除了出现劈手征外，还存在其他不同肌肉的劈裂现象。我们分析了 ALS 患者多个拮抗肌群分裂现象的发生率，并探讨了临床因素是否影响了其发生。

方法： 618 名 ALS 患者来自一个单一的 ALS 中心。使用改良的医学研究委员会 (MRC) 评分系统（范围从 1 到 13）评估上肢和下肢的肌肉力量。总结了不同拮抗肌群的分裂现象，并分析了与临床因素的相关性。

结果：在肘部屈伸拮抗肌中检测到分裂现象的比例为 22.3%，手腕为 11.9%，手指为 23.9%，脚踝为 18.2%，脚趾为 14.7%。这些表现的特点是肘部、腕部和手指伸肌与屈肌相比优先消瘦，踝和脚趾背屈肌与足底屈肌相比优先消瘦。当肌肉力量比改良的 MRC 6 级更强时，肌肉萎缩的存在更常见。 分裂现象与临床因素之间未发现明确的相关性，包括发病年龄、性别、病程、发病区域、和锥体束损伤。

讨论：ALS患者普遍存在拮抗肌群分裂现象。没有观察到影响这些现象发生的明确和一致的临床因素。