Sensorimotor integration underlying hand control in Carpal Tunnel Syndrome

描述(申请人提供)：对物体抓取和操纵的有效控制依赖于根据被抓住物体的属性(如重量、质心或质地)来调整单个手指的力的能力。这些调整依赖于(A)通过主要来自指尖和手部肌肉感受器的感觉反馈来检测物体属性，以及(B)将该反馈与适合抓握和操纵的手部肌肉的激活相结合。然而，手部肌肉活动对物体属性的微调可能会被一些神经和肌肉骨骼疾病破坏，如腕管综合征(CTS)。这种压迫正中神经的神经病是影响手功能的最常见和最衰弱的疾病之一。CTS会导致自我报告的手动灵活性丧失(例如，精细操作困难、物体掉落等)。这是由于拇指、食指、无名指中侧和外侧半指的躯体感觉障碍，在严重的情况下，拇指的运动障碍。由于全手抓取需要从所有手指感知物体属性以精确调整其作用力，因此CTS的研究为我们提供了一个独特的机会来提高我们对全手抓取和操作过程中感觉运动整合机制的理解。这一主要目标将通过使用CTS作为研究模型来实现，以解决抓取的感觉运动控制的这些重要问题。另一个次要目标是利用拟议的研究结果来提高我们对神经功能损伤增加对学习和执行熟练物体操作的特定方面所需的感觉-运动转换的程度的理解。我们将追求两个具体目标：(1)量化CTS患者在改变物体属性(重心、重量和质地)时能够协调所有指力和接触点的程度，以及它们在五位数抓取过程中的可预测性；(2)确定CTS患者能够协调指力的程度，作为抓取中涉及的数字(两、三、四和五)的函数。在这两个目标中，轻度和中度CTS患者的多维抓握控制措施将与年龄和性别匹配的健康对照组的多维控制措施进行比较。与公共卫生相关。拟议研究的目标与公共健康相关，因为他们解决了一种令人衰弱的手部神经肌肉疾病-腕管综合征(CTS)，该疾病影响了美国600万至1400万成年人的生活质量。我们建议使用CTS作为一个模型，以提高我们对负责熟练的物体操纵的感觉-运动整合的潜在机制的理解。通过我们拟议的研究获得的知识将为神经功能的电诊断测量如何与抓握控制的特定方面相关提供重要的洞察力，从而提高这些临床测量的可解释性和应用。

DESCRIPTION (provided by applicant): Effective control of object grasping and manipulation relies on the ability to adjust forces of individual digits to the properties of the object being grasped such as its weight, center of mass or texture. These adjustments rely on (a) detecting object properties through sensory feedback derived primarily from receptors in the fingertips and hand muscles and (b) integrating this feedback with activation of hand muscles appropriate for grasping and manipulation. However, the fine tuning of hand muscle activity to object properties can be disrupted by a number of neurological and musculo-skeletal diseases such as Carpal Tunnel Syndrome (CTS). This compresion neuropathy of the median nerve is one of the most common and debilitating diseases affecting hand function. CTS results in self-reported loss of manual dexterity (e.g., difficulties with fine manipulation, dropping objects, etc.) which is due to somatosensory deficits in the thumb, index, middle and lateral half of the ring finger, and, in severe cases, motor deficits in the thumb. As whole- hand grasping require sensing object properties from all digits to accurately adjust their forces, the study of CTS offers a unique opportunity to improve our understanding the mechanisms underlying sensorimotor integration during whole-hand grasping and manipulation. This primary objective will be pursued by using CTS as a research model to address these important questions of sensorimotor control of grasping. An additional secondary objective is to use the results of the proposed research to improve our understanding of the extent to which increasing impairment in nerve function affects sensorimotor transformations necessary for learning and executing specific aspects of skilled object manipulation. We will pursue two Specific Aims: (1) to quantify the extent to which patients with CTS are able to coordinate all digit forces and contact points when altering object properties (center of mass, weight and texture) and their predictability during five-digit grasping; and (2) to determine the extent to which patients with CTS are able to coordinate digit forces as a function of the number of digits (two, three, four, and five) involved in the grasp. In both Aims, multi-dimensional measures of grasp control from patients with mild and moderately severe CTS will be compared with those obtained from age- and gender-matched healthy controls. PUBLIC HEALTH RELEVANCE. The objectives of the proposed research are relevant to public health as they address a debilitating neuromuscular disease of the hand, Carpal Tunnel Syndrome (CTS), that affects the quality of life in 6 to 14 million adults in the United States. We propose to use CTS as a model to improve our understanding of the mechanisms underlying sensorimotor integration responsible for skilled object manipulation. The knowledge gained through our proposed research will provide significant insight into how electrodiagnostic measures of nerve function relate to specific aspects of grasp control, thus improving the interpretability and applications of these clinical measures.