Kronlage Cornelius, Grimm Alexander, Romano Alyssa, Stahl Jan-Hendrik, Martin Pascal, Winter Natalie, Marquetand Justus
Department of Neurology and Epileptology, University Hospital Tübingen and Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany.
Diagnostics (Basel). 2021 Jan 23;11(2):163. doi: 10.3390/diagnostics11020163.
Myotonia, i.e., delayed muscle relaxation in certain hereditary muscle disorders, can be assessed quantitatively using different techniques ranging from force measurements to electrodiagnostics. Ultrasound shear wave elastography (SWE) has been proposed as a novel tool in biomechanics and neuromuscular medicine for the non-invasive estimation of muscle elasticity and, indirectly, muscle force. The aim of this study is to provide 'proof-of-principle' that SWE allows a quantitative measurement of the duration of delayed muscle relaxation in myotonia in a simple clinical setting. In six myotonic muscle disorder patients and six healthy volunteers, shear wave velocities (SWV) parallel to the fiber orientation in the flexor digitorum superficialis muscle in the forearm were recorded with a temporal resolution of one per second during fist-clenching and subsequent relaxation; the relaxation time to 10% of normalized shear wave velocity (RT) was calculated. Forty-six SWE imaging sequences were acquired, yielding a mean RT of 7.38 s in myotonic muscle disorder patients, significantly higher than in healthy volunteers (1.36 s), which is comparable to data obtained by mechanical dynamometry. SWV measurements during the baseline relaxation and voluntary contraction phases did not differ significantly between groups. We conclude that SWE is a promising, non-invasive, widely available tool for the quantitative assessment of myotonia to aid in diagnosis and therapeutic monitoring.
肌强直，即在某些遗传性肌肉疾病中出现的肌肉松弛延迟现象，可以通过从力量测量到电诊断等不同技术进行定量评估。超声剪切波弹性成像（SWE）已被提议作为生物力学和神经肌肉医学中的一种新型工具，用于非侵入性估计肌肉弹性，并间接估计肌肉力量。本研究的目的是提供“原理验证”，即SWE能够在简单的临床环境中对肌强直时肌肉松弛延迟的持续时间进行定量测量。在6名患有肌强直肌肉疾病的患者和6名健康志愿者中，在前臂浅屈指肌中记录平行于纤维方向的剪切波速度（SWV），在握拳及随后放松过程中，时间分辨率为每秒1次；计算达到归一化剪切波速度10%时的松弛时间（RT）。采集了46个SWE成像序列，肌强直肌肉疾病患者的平均RT为7.38秒，显著高于健康志愿者（1.36秒），这与通过机械测力法获得的数据相当。在基线松弛和自主收缩阶段的SWV测量在两组之间没有显著差异。我们得出结论，SWE是一种有前景的、非侵入性的、广泛可用的工具，可用于肌强直的定量评估，以辅助诊断和治疗监测。
