PDF(Pubmed)
Abstract：
Task-specific dystonia leads to loss of sensorimotor control for a particular motor skill. Although focal in nature, it is hugely disabling and can terminate professional careers in musicians. Biomarkers for underlying mechanism and severity are much needed. In this study, we designed a keyboard device that measured the forces generated at all fingertips during individual finger presses. By reliably quantifying overflow to other fingers in the instructed (enslaving) and contralateral hand (mirroring) we explored whether this task could differentiate between musicians with and without dystonia. 20 right-handed professional musicians (11 with dystonia) generated isometric flexion forces with the instructed finger to match 25%, 50% or 75% of maximal voluntary contraction for that finger. Enslaving was estimated as a linear slope of the forces applied across all instructed/uninstructed finger combinations. Musicians with dystonia had a small but robust loss of finger dexterity. There was increased enslaving and mirroring, primarily during use of the symptomatic hand (enslaving p = 0.003; mirroring p = 0.016), and to a lesser extent with the asymptomatic hand (enslaving p = 0.052; mirroring p = 0.062). Increased enslaving and mirroring were seen across all combinations of finger pairs. In addition, enslaving was exaggerated across symptomatic fingers when more than one finger was clinically affected. Task-specific dystonia therefore appears to express along a gradient, most severe in the affected skill with subtle and general motor control dysfunction in the background. Recognition of this provides a more nuanced understanding of the sensorimotor control deficits at play and can inform therapeutic options for this highly disabling disorder.
摘要：
特定于任务的肌张力障碍导致对特定运动技能的感觉运动控制丧失。虽然在性质上是焦点，它严重残疾，可能会终止音乐家的职业生涯。非常需要潜在机制和严重程度的生物标志物。在这项研究中,我们设计了一种键盘设备，可以测量单个手指按压过程中所有指尖产生的力。通过可靠地量化指示（奴役）和对侧手（镜像）中其他手指的溢出，我们探索了该任务是否可以区分有和没有肌张力障碍的音乐家。20名惯用右手的专业音乐家（11名患有肌张力障碍）用指示的手指产生等距屈曲力，以匹配25％，该手指最大自愿收缩的50％或75％。随从被估计为在所有指示/未指示的手指组合上施加的力的线性斜率。患有肌张力障碍的音乐家的手指灵活性损失很小但很大。奴役和镜像增加了，主要是在使用有症状的手期间（奴役p=0.003；镜像p=0.016），以及无症状手的程度较小（奴役p=0.052；镜像p=0.062）。在所有手指对的组合中都看到了更多的奴役和镜像。此外,当不止一根手指受到临床影响时，有症状的手指的奴役被夸大了。因此，特定于任务的肌张力障碍似乎沿着梯度表达，在受影响的技能中最严重，背景是微妙和一般的运动控制功能障碍。对此的认识提供了对感觉运动控制缺陷的更细致的理解，并可以为这种高度致残的疾病提供治疗选择。
