Cortical mechanisms and modulation of somatosensation in older adults with foot sole somatosensory impairments

足底体感障碍老年人的皮质机制和体感调节

• 批准号: 10349812
• 负责人: Junhong Zhou
• 金额: $ 12.49万
• 依托单位: HEBREW REHABILITATION CENTER FOR AGED
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-01 至 2027-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10349812
• 关键词: Acute; Aging; Brain; Cerebral cortex; Chronic; Clinical; Complex; Contralateral; Custom; Data; Diffuse; Disease; Dose; Double-Blind Method; Elderly; Electrodes; Elements; Equilibrium; Esthesia; Exhibits; Fall prevention; Functional Magnetic Resonance Imaging; Gait; Goals; Impairment; Intervention; K-Series Research Career Programs; Knowledge; Learning; Left; Leg; Lower Extremity; Magnetic Resonance Imaging; Measures; Mentored Research Scientist Development Award; Modeling; Nerve; Nervous System Physiology; Neuraxis; Participant; Pathway interactions; Peripheral; Peripheral Nerves; Peripheral Nervous System; Population; Porifera; Process; Protocols documentation; Randomized; Research; Scalp structure; Scientist; Sensory; Sensory Process; Somatosensory Cortex; Specific qualifier value; Stimulus; System; Techniques; Technology; Testing; Therapeutic; Training; Visit; Walking; Work; age related; base; blood oxygenation level dependent response; career; clinical care; cognitive function; design; electric field; experience; fall risk; falls; foot; foot sole; functional restoration; improved; locomotor control; neuroimaging; neurophysiology; noninvasive brain stimulation; novel; novel therapeutics; pressure; programs; receptor; response; screening; sensory feedback; somatosensory; tactile stimulation; therapy design

PROPOSAL SUMMARY My career goals are to 1) understand the supraspinal sensorimotor pathways through which age- and age- related conditions diminish the functionality of the locomotor control system, and 2) use this information to develop new therapies to improve gait and balance in older adults. I hope to achieve this goal by transitioning into an independent scientist and leading an research program in the fields of aging and balance control. In older adults, diminished lower-extremity somatosensation is highly prevalent and a primary contributor to poor balance, reduced mobility, and increased risk of falling. The vast majority of research and clinical efforts to date have attempted to improve somatosensation by restoring the function of peripheral elements of the somatosensory system. However, somatosensation is also dependent upon the capacity to activate the appropriate cortical networks in response to a given stimulus, which is also altered in older adults. Therapeutic strategies aimed at enhancing the excitability of the somatosensory cortical network thus offer untapped potential to improve foot-sole somatosensation in this population. Our preliminary studies suggest that a single session of traditional transcranial direct current stimulation (tDCS), which produces a diffuse electric field over the primary somatosensory cortex, improves foot-sole somatosensation in older adults. In this K01 Award, we will first work to identify the specific cortical network that is responsive to walking-related foot-sole stimulation in older adults with and without foot-sole somatosensation (Aim 1). We will use a block-design functional MRI paradigm with a custom-designed, MRI-compatible foot sole stimulation system to apply individualized pressures to the participant’s foot soles that mimic those experienced when they walk, yet while they lay motionless in the scanner. Based upon this knowledge obtained from Aim 1, we will develop a novel multi- target tDCS intervention targeting the identified cortical network and test the effects of a single session of this intervention on foot-sole somatosensation, balance and mobility in older adults with mild-to-moderate foot-sole somatosensory impairments (Aim 2). We will then use participant brain MRIs and electric field modeling to establish the “dose-response” relationship between on-target current intensity induced by tDCS and its acute effect on the cortical response to foot sole stimulation (Aim 3). Through this work we will learn about how chronic lower-extremity somatosensory impairments influence the cortical processing of sensory feedback involved in the control of balance and mobility, demonstrate that such processing can be modulated by tDCS, and thus, obtain critical information needed to design a larger more definitive trial to test the potential for tDCS to improve foot sole sensation, balance, and mobility in this population. This career development award will provide me with unique training experiences in neurophysiology of somatosensation in aging, the clinical care of these older adults, and increase my expertise in advanced neuroimaging and brain stimulation techniques, which, taken together, will greatly facilitate my efforts to transition into an independent academic scientist.

提案摘要 我的职业目标是 1）了解年龄和年龄所通过的脊髓上感觉运动通路 相关条件会削弱运动控制系统的功能，并且 2）使用此信息 开发新疗法来改善老年人的步态和平衡，我希望通过过渡来实现这一目标。 成为一名独立科学家，领导衰老和平衡控制领域的研究项目。 在老年人中，下肢躯体感觉减退非常普遍，也是导致这种情况的主要原因 绝大多数研究和临床工作都导致平衡能力差、活动能力下降和跌倒风险增加。 迄今为止，尝试通过恢复周围元件的功能来改善体感 然而，体感也取决于激活体感系统的能力。 适当的皮质网络对给定的刺激作出反应，这在老年人的治疗中也会发生改变。 因此，旨在增强体感皮质网络兴奋性的策略提供了尚未开发的机会 我们的初步研究表明，有可能改善该人群的脚底躯体感觉。 传统的经颅直流电刺激 (tDCS) 过程，会在上方产生扩散电场 初级体感皮层，改善老年人的脚底体感。在这个 K01 奖中，我们。 首先将致力于识别对步行相关的足底刺激做出反应的特定皮质网络 对于有或没有足底躯体感觉的老年人（目标 1），我们将使用块设计功能 MRI。 具有定制设计、与 MRI 兼容的足底刺激系统的范例，以应用个性化 参与者脚底承受的压力模仿他们行走时和躺着时所经历的压力 基于从目标 1 获得的知识，我们将开发一种新颖的多功能传感器。 针对已识别的皮质网络进行目标 tDCS 干预，并测试单个会话的效果 对轻中度足底老年人足底躯体感觉、平衡和活动能力的干预 然后，我们将使用参与者的大脑 MRI 和电场建模来检测体感障碍（目标 2）。 建立 tDCS 诱导的目标电流强度与其急性发作之间的“剂量-反应”关系 对脚底刺激的皮质反应的影响（目标 3）。 慢性下肢体感障碍影响感觉反馈的皮层处理 参与平衡和活动性的控制，证明这种处理可以通过 tDCS 进行调节， 因此，获得设计更大规模、更明确的试验所需的关键信息，以测试 tDCS 的潜力 该职业发展奖将改善这一人群的脚底感觉、平衡和活动能力。 为我提供了独特的衰老体感神经生理学、临床护理方面的培训经验 这些老年人，并增加我在先进神经影像和大脑刺激技术方面的专业知识， 总而言之，这将极大地促进我向独立学术科学家转变的努力。