A New Method for Functional Evaluation of Motor Commands in Patients with Cerebellar Ataxia.
A New Method for Functional Evaluation of Motor Commands in Patients with Cerebellar Ataxia.
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DOI：
10.1371/journal.pone.0132983
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Kakei S
中科院分区：
文献类型：
--
作者：
Lee J;Kagamihara Y;Kakei S
定量评估小脑共济失调患者的运动功能对于循证治疗至关重要，并且一直是之前运动运动学研究的焦点。由于肌肉骨骼系统的冗余性，肌肉活动包含了比运动学更多的信息。因此，最好是分析肌肉活动的因果异常，以评估患者的运动功能。在这里，我们提出了一种新的方法来评估运动功能的肌肉活动和运动学的水平。19名患者和10名对照受试者进行了两项运动任务的腕关节，一个步骤跟踪任务和追求任务，与一个巨大的操纵。记录腕关节的运动和四个腕关节原动机的活动。我们开发了一个线性模型的腕关节近似的肌肉活动和运动运动学之间的因果关系的腕关节扭矩。我们使用典型相关分析来验证模型中肌肉活动和运动学之间的因果关系。我们发现，四块肌肉的活动几乎完全与位置和速度有关，与腕关节加速度的相关性可以忽略不计。此外，位置和速度相关的扭矩分量的重量比的特点的肌肉活动的内容在运动学方面。接下来，我们比较了对照组和患者之间两种运动任务的比率。在对照组中，比率表明明确的任务特定的变化，符合功能要求的任务。相比之下，在患者中，任务特异性变化非常显着减少。目前的研究结果表明，这种能力，以适应运动命令的任务要求提供了一个新的定量参数来表征运动功能的小脑共济失调患者。
Quantitative evaluation of motor functions of patients with cerebellar ataxia is vital for evidence-based treatments and has been a focus in previous investigations of movement kinematics. Due to redundancy of the musculoskeletal system, muscle activities contain more information than the movement kinematics. Therefore, it is preferable to analyze causal anomalies of muscle activities to evaluate motor functions in patients. Here we propose a new method to evaluate the motor functions at the level of muscle activities and movement kinematics. Nineteen patients and 10 control subjects performed two movement tasks of the wrist joint, a step-tracking task and a pursuit task, with a manipulandum. The movements of the wrist joint and activities of the four wrist prime movers were recorded. We developed a linear model for the wrist joint to approximate the causal relationship between muscle activities and movement kinematics in terms of the wrist joint torque. We used a canonical correlation analysis to verify the causality between the muscle activities and the movement kinematics in the model. We found that the activities of the four muscles were related almost entirely to the position and velocity, with negligible correlation with the acceleration of the wrist joint. Moreover, the ratio of the weights for position- and velocity-related torque components characterized the contents of the muscle activities in terms of the movement kinematics. Next, we compared the ratios for the two movement tasks between the controls and patients. In control subjects, the ratios indicated clear task-specific changes that conformed to the functional requirements of the tasks. In contrast, in patients, the task-specific changes diminished highly significantly. The present results indicate that this ability to accommodate motor commands to the task requirements provides a novel quantitative parameter to characterize motor functions in patients with cerebellar ataxia.