Spinal excitation to enhance mobility in elderly adults

脊髓兴奋增强老年人的活动能力

• 批准号: 10247445
• 负责人: David J Clark
• 金额: --
• 依托单位: VETERANS HEALTH ADMINISTRATION
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-11-01 至 2021-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10247445
• 关键词: Action Potentials; Adult; Affect; Age; Aging; American; Area; Behavioral; Biomechanics; Blinded; Brain; Communities; Community Surveys; Complex; Data; Elderly; Electrodes; Feedback; Fire - disasters; Future; Goals; H-Reflex; Hospitalization; Impairment; Intervention; Lead; Leg; Literature; Measures; Membrane Potentials; Morbidity - disease rate; Motor; Movement; Near-Infrared Spectroscopy; Nervous system structure; Neuronal Plasticity; Neurons; Noise; Participant; Pattern; Performance; Peripheral; Peripheral Nerves; Personal Satisfaction; Quality of life; Randomized; Rehabilitation therapy; Research; Research Design; Risk; Risk Factors; Shoes; Signal Transduction; Skin; Soleus Muscle; Spinal; Spinal Cord; Spinal cord injury; Standardization; Structure; Techniques; Testing; Texture; Translating; Veterans; Visit; Walking; Work; adverse outcome; age related; combinatorial; cost; design; executive function; falls; improved; improved mobility; locomotor control; male; military veteran; mortality; neural circuit; neuroregulation; relating to nervous system; response; sensory input; somatosensory; transmission process; walking speed; wearable sensor technology; Action Potentials; Adult; Affect; Age; Aging; American; Area; Behavioral; Biomechanics; Blinded; Brain; Communities; Community Surveys; Complex; Data; Elderly; Electrodes; Feedback; Fire - disasters; Future; Goals; H-Reflex; Hospitalization; Impairment; Intervention; Lead; Leg; Literature; Measures; Membrane Potentials; Morbidity - disease rate; Motor; Movement; Near-Infrared Spectroscopy; Nervous system structure; Neuronal Plasticity; Neurons; Noise; Participant; Pattern; Performance; Peripheral; Peripheral Nerves; Personal Satisfaction; Quality of life; Randomized; Rehabilitation therapy; Research; Research Design; Risk; Risk Factors; Shoes; Signal Transduction; Skin; Soleus Muscle; Spinal; Spinal Cord; Spinal cord injury; Standardization; Structure; Techniques; Testing; Texture; Translating; Veterans; Visit; Walking; Work; adverse outcome; age related; combinatorial; cost; design; executive function; falls; improved; improved mobility; locomotor control; male; military veteran; mortality; neural circuit; neuroregulation; relating to nervous system; response; sensory input; somatosensory; transmission process; walking speed; wearable sensor technology

It is well known that age-related impairments of the brain and peripheral nerves contribute to a decline in walking function. Age-related impairment of the spinal cord is also a likely contributing factor, as the literature describes a variety of changes in spinal cord structure and function with aging. Specifically, the elderly spinal cord is less excitable, conducts signals more slowly, and is subject to neural noise. Therefore, we are initiating a new line of research with the goal of enhancing walking function in elderly Veterans by intervening on age- related neural impairment of the spinal cord. The objective of the proposed study is to establish the feasibility, preliminary efficacy, and variance of response for using transcutaneous spinal direct current stimulation (tsDCS) and textured shoe insoles to excite spinal locomotor circuits and enhance practice-related performance and retention on an obstacle walking task. Enhanced practice and retention effects will support future efforts to translate this approach into a longer term rehabilitation intervention. Excitatory tsDCS is a non-invasive neuromodulation approach in which a relatively weak electrical current is delivered to the desired region of the spinal cord via electrodes placed on the skin. The electrical current does not cause discharge of action potentials, but rather is designed to bring neurons closer to their discharge threshold by inducing a sub-threshold depolarization of membrane potentials. When combined with a behavioral task, tsDCS has the potential to upregulate neural circuits in a task-specific manner and promote Hebbian neuroplasticity (‘fire together, wire together’). We will use a previously established electrode montage to deliver excitatory tsDCS to the lumbosacral spinal cord during practice of a complex obstacle walking task. We also propose to combine the use of textured shoe insoles with tsDCS. This combinatorial approach may be a potent strategy for simultaneously optimizing spinal responsiveness to input from both descending and ascending excitatory signals to spinal centers of locomotor control. One anticipated benefit of increasing the excitation of spinal locomotor circuits is a reduction in the executive demand of walking, as measured by prefrontal cortical activation. Our research shows that elderly adults rely heavily on compensatory executive control while walking. This is widely considered to be a risk factor for adverse outcomes including falls. We propose a parallel groups study design in which 40 older adults who have walking deficits and who demonstrate a compensatory executive locomotor control strategy will be randomized into one of four groups: 1) active tsDCS with smooth insoles (active/smooth); 2) sham tsDCS with smooth insoles (sham/smooth); 3) active tsDCS with textured insoles (active/textured); and 4) sham tsDCS with textured insole (sham/textured). Participants will be blinded to group assignment. While receiving stimulation, participants will engage in 20 minutes of walking practice over a standardized obstacle course. Immediately prior to and following the practice, each participant will be assessed while walking over the course at their fastest safe pace. Practice- related gains in performance will be quantified by walking speed and other biomechanical metrics. Retention of performance gains will also be assessed at a separate visit 2 days later. tsDCS-induced changes in spinal excitability will be assessed by measuring soleus H-reflex. Executive demand of walking will be assessed as prefrontal cortical activation, measured with functional near infrared spectroscopy (fNIRS). Intervening on age- related impairment of the spinal cord to improve walking function is a promising but untapped area of research. The proposed intervention techniques are low cost and translatable to real-world settings, which enhances the potential long term impact of this work on the well-being of aging Veterans.

众所周知，与年龄相关的大脑和周围神经系统的损害有助于下降 步行功能。脊髓与年龄相关的损害也可能导致因素，因为文献 描述了随着衰老的脊髓结构和功能的各种变化。具体而言，脊柱较早 绳索不那么令人兴奋，引起信号的速度较慢，并且会受到神经噪声的影响。因此，我们被启动 一项新的研究系列，目的是通过介入年龄来增强老退伍军人的步行功能 - 脊髓的相关神经增强。拟议的研究的目的是确定可行性 初步效率和使用经皮脊柱直流刺激的响应方差 （TSDC）和纹理的鞋具，以激发脊柱运动电路并增强与练习有关的 在障碍行走任务上的性能和保留。增强的实践和保留效果将支持 将这种方法转化为长期康复干预措施的未来努力。 兴奋性TSDC是一种非侵入性神经调节方法，其中相对较弱的电流为 通过置于皮肤上的电子传递到脊髓所需的区域。电流确实 不会引起动作电位的排放，而是旨在使神经元更接近其排出 通过诱导膜电位的亚阈值沉积的阈值。当与 行为任务，TSDC有可能以特定于任务的方式上调神经回路并促进 Hebbian神经塑性（“一起火，一起火”）。我们将使用先前建立的电极蒙太奇 在练习复杂的障碍行走任务期间，将兴奋性TSDC传递到腰脊髓。 我们还建议将纹理鞋鞋垫的使用与TSDC结合使用。这种组合方法可能是 简单地优化对下降和脊柱响应的潜在策略 上升兴奋信号到运动控制的脊柱中心。一个预期的好处是增加 脊柱运动电路的激发是行走的行政需求的减少，如 前额叶皮质激活。我们的研究表明，年长的成年人严重依赖薪酬高管 步行时控制。这被广泛认为是包括瀑布在内的广告结果的危险因素。 我们提出了一个平行的小组研究设计，其中40名具有步行不足的老年人以及谁 证明代偿性执行运动控制策略将被随机分为四组之一： 1）具有光滑鞋垫的主动TSDC（活动/光滑）； 2）带有光滑鞋垫的假TSDC（假/平滑）； 3） 具有纹理鞋垫的活动TSDC（活动/纹理）； 4）带有纹理鞋垫的假TSDC（假/纹理）。 参与者将对小组分配视而不见。在接受刺激的同时，参与者将参与20 在标准化障碍物过程中步行分钟。紧接之前和之后 练习，每个参与者将在最快的安全空间上行走时进行评估。实践- 步行速度和其他生物力学指标将量化相关性能的相关增长。保留 两天后，还将在另一次访问中评估性能增长。 TSDC诱导的脊柱变化 兴奋性将通过测量比反射测量来评估。行走的行政需求将被评估为 前额叶皮质激活，通过功能性近红外光谱（FNIRS）测量。介入年龄 - 脊髓相关的损害以改善步行功能是一个尚未开发的研究领域。 拟议的干预技术是低成本，可转换为现实世界的设置，这增强了 这项工作对老化退伍军人的福祉的潜在长期影响。