Mechanisms underlying impaired postural corrections following stroke

中风后姿势矫正受损的机制

• 批准号: 8703734
• 负责人: CLAIRE F. HONEYCUTT
• 金额: $ 11.03万
• 依托单位: REHABILITATION INSTITUTE OF CHICAGO D/B/A SHIRLEY RYAN ABILITYLAB
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2015-02-04
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8703734
• 关键词: Accounting; Address; Agonist; Automobile Driving; Bilateral; Caring; Complex; Data; Development; Effectiveness; Elderly; Electromyography; Equilibrium; Exercise; Fall prevention; Family; Flexor; Future; Goals; Hospitals; Impairment; Incidence; Individual; Intervention; Involuntary Movements; Knowledge; Lead; Limb structure; Link; Measures; Mediating; Motor; Movement; Muscle; Outcome Study; Patients; Pattern; Performance; Persons; Population; Prevention program; Public Health; Quality of life; Recovery; Reflex action; Rehabilitation therapy; Reporting; Risk Factors; Role; Shapes; Solutions; Stereotyping; Stimulus; Stroke; Surface; Survivors; Time; Toes; Training; Training Programs; Translations; United States; Weight; Work; arm; base; cost; effective therapy; fall risk; falls; improved; kinematics; limb movement; medical complication; post stroke; programs; public health relevance; relating to nervous system; response

DESCRIPTION: Fall prevention programs have had mixed results highlighting the need for more effective therapies that tackle the most common medical complication in stroke survivors. Task-specific training, which directly targets improving an individual's response during a fall, offers potential. The long-term goal of this proposal is to develop task-specific training that accounts for the unique balance challenges of stroke survivors that is both effective and time efficient. The ability to implement a task-specific training program in stroke survivors is thwarte by a lack of empirical evidence about which factors and mechanisms lead to a failed recovery during a balance disturbance in this population. An essential component of a successful recovery (avoidance of a fall) is compensatory limb movement - taking a step to regain balance or reaching to a stable surface. The PIs recently noted important similarities between compensatory movements and startle-evoked movements - the involuntary release of planned movement when exposed to startling stimuli. Specifically, startle-evoked and compensatory movements share similar deficits following stroke - delayed, diminished muscle activity, and inappropriate patterns of muscle activation. Thus the PIs' central hypothesis is that deficits in compensatory movements post-stroke are driven by deficits in startle-evoked movements. In Aim 1, the objective is to quantify stroke survivors' response during a balance disturbance identifying the key, trainable factors that lead to unsuccessful recovery (i.e. a fall). In brief, stroke survivors will be exposed to backward translations of a treadmill while quantifying stabilit measures, trunk and step kinematics, paretic limb parameters, and electromyography. Factors will be assessed for their ability to classify successful (fall avoidance) and failed (fall) recoveies. These factors can then be assessed for trainability in future task-specific training paradigms for stroke survivors. In Aim 2, the PIs will pursue identification of the mechanism driving deficits in compensatory movements to arm perturbation in stroke survivors. The objective is to evaluate the impact of deficits in startle-evoked movement on the ability of stroke survivors to effectively compensate during an arm perturbation. To precisely control perturbation parameters and allow bilateral assessment of paretic and non-paretic limbs, the PIs will evaluate subjects while seated. In Aim 3, the PIs will combine knowledge gained in Aims 1 & 2 and evaluate the link between factors that contribute to falls and the mechanisms proposed. The objectives are to 1) evaluate the link between triggering a startle-evoked movement and successful compensatory movement during a balance challenge in unimpaired individuals and 2) evaluate the relationship between deficits in startle-evoked movement and deficits in compensatory limb movements post-stroke. The rationale for the proposal is to establish both the factors and mechanisms driving unsuccessful recovery during a fall post-stroke in order to generate an effective task-specific training paradigm in the next application.

产品说明：跌倒预防计划的结果喜忧参半，强调需要更有效的治疗方法来解决中风幸存者最常见的医疗并发症。针对特定任务的训练，直接针对改善个人在跌倒时的反应，提供了潜力。该提案的长期目标是开发针对特定任务的培训，以应对中风幸存者独特的平衡挑战，既有效又省时。在中风幸存者中实施特定任务训练计划的能力受到缺乏经验证据的阻碍，这些证据表明哪些因素和机制导致该人群在平衡障碍期间恢复失败。成功恢复（避免跌倒）的一个重要组成部分是肢体的补偿运动-采取措施恢复平衡或达到稳定的表面。PI最近注意到补偿运动和惊吓诱发运动之间的重要相似之处-当暴露于惊人的刺激时，计划运动的无意识释放。具体而言，中风后的惊吓诱发和代偿性运动具有相似的缺陷-延迟、肌肉活动减少和肌肉激活模式不适当。因此，PI的中心假设是中风后代偿运动的缺陷是由惊吓诱发运动的缺陷驱动的。在目标1中，目标是量化中风幸存者在平衡障碍期间的反应，识别导致不成功恢复（即跌倒）的关键可训练因素。简而言之，卒中幸存者将暴露于跑步机的向后平移，同时量化稳定性测量、躯干和脚步运动学、麻痹肢体参数和肌电图。将评估因素对成功（避免跌倒）和失败（跌倒）恢复进行分类的能力。这些因素可以在未来的任务特定的训练模式中风幸存者的可训练性进行评估。在目标2中，主要研究者将致力于确定以下方面的赤字驱动机制： 脑卒中幸存者对手臂扰动的代偿性运动。本研究的目的是评估惊吓诱发运动缺陷对卒中幸存者有效地进行运动能力的影响。 在臂扰动期间进行补偿。为了精确控制扰动参数并允许双侧评估轻瘫和非轻瘫肢体，PI将在坐位时评估受试者。在目标3中，PI将结合目标1和2中获得的联合收割机知识，并评估导致福尔斯的因素与提出的机制之间的联系。目的是：1）评价未受损个体在平衡挑战期间触发惊吓诱发运动和成功代偿运动之间的联系; 2）评价中风后惊吓诱发运动缺陷和代偿肢体运动缺陷之间的关系。该提案的基本原理是建立中风后跌倒期间导致恢复不成功的因素和机制，以便在下一个应用中产生有效的特定任务训练范例。