Changing a reflex to improve locomotion

改变反射以改善运动

• 批准号: 8039496
• 负责人: Aiko Thompson
• 金额: $ 25.22万
• 依托单位: HELEN HAYES HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8039496
• 关键词: Accounting; Acute; Affect; Aftercare; Animals; Ankle; Behavior; Chronic; Complement; Conditioned Reflex; Data; Development; Gait; Goals; H-Reflex; Human; Hyperreflexia; Individual; Injury; Learning; Life; Locomotion; Lower Extremity; Methods; Modification; Monkeys; Motor; Movement; Muscle; Natural regeneration; Neuraxis; Operant Conditioning; Pathway interactions; Pattern; Phase; Population; Procedures; Protocols documentation; Rattus; Recovery; Recovery of Function; Reflex action; Rehabilitation therapy; Shapes; Skeletal Muscle; Spastic; Spastic Gait; Speed; Spinal; Spinal cord injury; Techniques; Testing; Therapeutic Effect; Walking; Work; abnormal reflex; analog; animal data; base; conditioning; conventional therapy; disability; human data; human subject; improved; kinematics; novel therapeutic intervention; public health relevance; restoration; spinal reflex; stretch reflex

DESCRIPTION (provided by applicant): People with incomplete spinal cord injury (SCI) often have substantial disabilities, even after completing conventional therapy. Common motor abnormalities after SCI include spasticity and weak voluntary muscle control. Altered spinal reflex pathways contribute to these problems. In this population, exaggerated stretch reflex and abnormal reflex modification of the ankle extensors are frequently observed. Normally, spinal reflexes are modulated from standing to walking, and during walking reflexes are further modulated between different phases of the gait cycle. However, in individuals after SCI, modulation of the soleus H-reflex during walking is often absent or greatly diminished (i.e., the reflex amplitude remains high even in the early stance or swing phase, where the H-reflex is normally very small or absent). Spinal reflexes can be changed through operant conditioning. Previous work in rats and monkeys shows that successful operant conditioning of a spinal reflex changes not only the reflex pathway that is conditioned but also the activity of other spinal and supraspinal pathways. Therefore, it may be possible to guide central nervous system plasticity associated with learning to change the activity of a spinal reflex pathway such that movement disabilities can be ameliorated. The goal of this project is to investigate the impact of changing a spinal reflex on impaired locomotion after chronic incomplete SCI in people. In humans, reflex conditioning with a far smaller number of trials per day than those used in rats can produce a comparable amount of reflex change. Recent work in rats shows that soleus H-reflex operant conditioning changes soleus behavior during locomotion, and indicates that appropriate conditioning can improve locomotion after incomplete SCI. Based on these findings, this project will test two hypotheses. The first hypothesis is that, in subjects with spastic hyperreflexia due to chronic incomplete SCI, decreasing the soleus H-reflex by operant down-conditioning can improve locomotion. The second hypothesis is that, locomotion can be further improved by applying down-conditioning procedures during appropriate phases of locomotion, when the H-reflex should normally be absent. These hypotheses will be tested by applying down-conditioning of the soleus H-reflex in spastic subjects with incomplete SCI. The impact of conditioning on the locomotor EMG activity, reflex modulation during gait, gait kinematics, and walking speed will be assessed, before and after conditioning. We will also assess the persistence of these effects. We expect to find that successful H-reflex down-conditioning can improve locomotion recovery after incomplete SCI and that this improvement will persist. Successful completion of this project will facilitate development of spinal reflex operant conditioning as a new, therapeutic approach to improving motor function recovery for individuals after SCI. This new method should complement existing methods and augment restoration of useful function. PUBLIC HEALTH RELEVANCE: With recent advances in acute care after spinal cord injury (SCI), which has resulted in more cases of incomplete SCI, and development of regeneration therapies, rehabilitation for functional recovery is becoming increasingly important for re-establishing an active, productive, fulfilling life in these individuals. In order to maximize functional recovery after SCI, it is extremely important to continue developing new therapeutic approaches beyond conventional rehabilitation techniques. The goal of this project is to investigate the therapeutic effects of changing a spinal reflex on impaired locomotion after chronic incomplete SCI. Successful completion of this project will open up a new therapeutic approach for treating individuals after SCI.

描述（由申请人提供）：不完全性脊髓损伤（SCI）的患者即使在完成常规治疗后，也往往有严重的残疾。SCI后常见的运动异常包括痉挛和随意肌控制能力弱。脊髓反射通路的改变导致了这些问题。在这个人群中，经常观察到踝伸肌的过度牵张反射和异常反射修改。正常情况下，脊髓反射从站立到行走被调节，并且在行走期间，反射在步态周期的不同阶段之间被进一步调节。然而，在SCI后的个体中，行走期间比目鱼肌H反射的调节通常不存在或大大减弱（即，反射幅度甚至在早期站立或摆动阶段也保持高，其中H反射通常非常小或不存在）。 脊髓反射可以通过操作性条件反射改变。先前在大鼠和猴子身上的研究表明，脊髓反射的成功操作性条件反射不仅改变了条件反射通路，而且还改变了其他脊髓和脊髓上通路的活动。因此，可以引导与学习相关的中枢神经系统可塑性以改变脊髓反射通路的活动，从而可以改善运动障碍。该项目的目的是研究改变脊髓反射对慢性不完全性SCI后运动障碍的影响。 在人类中，每天的反射条件反射试验次数远少于大鼠，但产生的反射变化量却相当。最近的研究表明，比目鱼肌H反射操作性条件反射改变运动过程中的比目鱼肌行为，并表明适当的条件反射可以改善不完全SCI后的运动。根据这些发现，本项目将检验两个假设。第一个假设是，在由于慢性不完全性SCI而导致痉挛性反射亢进的受试者中，通过操作性下调节降低比目鱼肌H反射可以改善运动。第二个假设是，当H反射通常不存在时，运动可以通过在运动的适当阶段应用向下调节程序来进一步改善。 这些假设将通过在不完全SCI的痉挛受试者中应用比目鱼肌H反射的向下调节来测试。将在调节前后评估调节对运动EMG活动、步态期间反射调制、步态运动学和步行速度的影响。我们还将评估这些影响的持续性。我们期望发现成功的H反射下调可以改善不完全SCI后的运动恢复，并且这种改善将持续下去。成功完成这个项目将促进脊髓反射操作性条件反射的发展，作为一种新的治疗方法，以改善SCI后个人的运动功能恢复。这种新方法应补充现有的方法，并增加有用功能的恢复。 公共卫生相关性：随着脊髓损伤（SCI）后急性护理的最新进展，这导致了更多的不完全SCI病例，以及再生疗法的发展，功能恢复的康复对于重建这些个体的积极，富有成效，充实的生活变得越来越重要。为了最大限度地恢复SCI后的功能，继续开发超越传统康复技术的新治疗方法是非常重要的。本项目的目的是研究改变脊髓反射对慢性不完全性脊髓损伤后运动障碍的治疗效果。该项目的成功完成将为治疗SCI后的个体开辟一种新的治疗方法。