Sensorimotor integration underlying hand control in Carpal Tunnel Syndrome

描述（由申请人提供）：对物体抓取和操作的有效控制依赖于根据被抓取物体的属性（如重量、质心或质地）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的感受器的感觉反馈来检测物体特性，(b)将这种反馈与适合抓握和操作的手部肌肉的激活相结合。然而，手部肌肉活动对物体特性的精细调节可能会被一些神经和肌肉骨骼疾病（如腕管综合征）所破坏。这种压迫正中神经的神经病变是影响手功能的最常见和衰弱性疾病之一。CTS导致自我报告的手灵巧性丧失（例如，精细操作困难，掉落物体等），这是由于拇指，食指，无名指中部和外侧半部分的体感缺陷，在严重的情况下，拇指的运动缺陷。由于全手抓取需要感知所有手指的物体属性来准确调整其力量，CTS的研究为我们理解全手抓取和操作过程中感觉运动整合的机制提供了一个独特的机会。这一主要目标将通过使用CTS作为研究模型来解决抓握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研究的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必需的感觉运动转换的影响程度的理解。我们将追求两个具体目标：(1)量化CTS患者在改变物体属性（质心，重量和质地）时能够协调所有手指力量和接触点的程度及其在五指抓取过程中的可预测性；(2)确定CTS患者能够协调手指力量的程度，作为抓握中涉及的手指数量（二、三、四、五）的函数。在这两项研究中，将对轻、中重度CTS患者的抓握控制的多维测量与年龄和性别匹配的健康对照进行比较。公共卫生相关性。拟议研究的目标与公共卫生有关，因为它们涉及手部的一种使人衰弱的神经肌肉疾病——腕管综合征（Carpal Tunnel Syndrome， CTS），它影响着美国600万至1400万成年人的生活质量。我们建议使用CTS作为模型来提高我们对负责熟练物体操作的感觉运动整合机制的理解。通过我们提出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见解，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.