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

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损伤会导致智力下降。 正如文献所述，与年龄相关的脊髓损伤也是一个可能的影响因素。 描述了脊髓结构和功能随着衰老而发生的各种变化，特别是老年人的脊髓。 脊髓不太兴奋，传导信号更慢，并且容易受到神经噪音的影响，因此，我们正在启动。 一项新的研究，旨在通过干预年龄来增强老年退伍军人的步行功能 所提出的研究的目的是确定可行性， 使用经皮脊髓直流电刺激的初步疗效和反应方差 (tsDCS) 和纹理鞋垫可激发脊髓运动回路并增强与练习相关的能力 障碍行走任务的表现和记忆力的增强将有助于提高练习和记忆力。 未来将努力将这种方法转化为长期康复干预措施。 兴奋性 tsDCS 是一种非侵入性神经调节方法，其中相对较弱的电流 电流通过放置在皮肤上的电极输送到脊髓的所需区域。 不会引起动作电位的放电，而是旨在使神经元更接近其放电 当与膜电位结合时，通过诱导膜电位的亚阈值去极化来降低阈值。 行为任务，tsDCS 有潜力以特定任务的方式上调神经回路并促进 赫布神经可塑性（“一起点火，一起接线”）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向腰骶脊髓传递兴奋性 tsDCS。 我们还建议将纹理鞋垫与 tsDCS 结合使用，这种组合方法可能是。 同时优化脊柱对下行和下行输入的反应性的有效策略 增加兴奋性信号到脊髓运动控制中心的一个预期好处。 脊髓运动回路的兴奋是步行执行需求的减少，测量如下： 我们的研究表明，老年人严重依赖补偿性执行功能。 这被广泛认为是导致跌倒等不良后果的危险因素。 我们提出了一项平行小组研究设计，其中 40 名有步行缺陷的老年人和 展示补偿性执行运动控制策略将被随机分为四组之一： 1) 具有平滑鞋垫的主动 tsDCS（主动/平滑）；2) 具有平滑鞋垫的假 tsDCS（假/平滑）； 具有纹理鞋垫的主动 tsDCS（主动/纹理）；和 4）具有纹理鞋垫的假 tsDCS（假/纹理）。 参与者将不知道小组分配，同时接受刺激，参与者将参与 20 项活动。 在标准障碍训练场之前和之后进行几分钟的步行练习。 练习时，每个参与者将以最快的安全速度在赛道上行走时接受评估。 相关的表现提升将通过步行速度和其他生物力学指标来量化。 还将在 2 天后的单独访视中评估 tsDCS 引起的脊柱变化。 兴奋性将通过测量比目鱼肌 H 反射来评估，步行的执行需求将被评估为。 前额皮质激活，通过功能近红外光谱（fNIRS）测量年龄干预。 通过脊髓相关损伤来改善行走功能是一个有前途但尚未开发的研究领域。 所提出的干预技术成本低廉，并且可以转化为现实世界的环境，从而增强了 这项工作对老年退伍军人的福祉的潜在长期影响。