Probing an increased reliance on reticulospinal motor pathways in chronic hemiparetic stroke with advanced spinal cord functional MRI

利用先进的脊髓功能 MRI 探讨慢性偏瘫卒中对网状脊髓运动通路的依赖性增加

• 批准号: 10750576
• 负责人: Kimberly Jiyun Hemmerling
• 金额: $ 4.35万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10750576
• 关键词: Address; Affect; Automobile Driving; Bilateral; Brachial Paresis; Brain; Cervical; Cervical spinal cord structure; Characteristics; Chronic; Communication; Contralateral; Dedications; Development; Diffuse; Distal; Electromyography; Environment; Fellowship; Fostering; Functional Magnetic Resonance Imaging; Generations; Goals; Hand; Handedness; Human; Imaging Techniques; Impairment; Individual; Injury; Intervention; Ipsilateral; Isometric Exercise; Joints; Leadership; Limb structure; Link; Magnetic Resonance Imaging; Maps; Measures; Mediating; Medical; Mentorship; Methods; Motor; Motor Activity; Motor Neurons; Motor Pathways; Movement; Muscle; National Research Service Awards; Neural Pathways; Neuronal Plasticity; Neurophysiology - biologic function; Neurosciences; Noise; Paresis; Participant; Pathway interactions; Pattern; Physiological; Positioning Attribute; Predisposition; Reaction; Recovery of Function; Rehabilitation therapy; Research; Research Project Grants; Research Proposals; Severities; Side; Signal Transduction; Skeletal Muscle; Spinal; Spinal Cord; Statistical Models; Stroke; Techniques; Therapeutic Intervention; Training; United States; Universities; Up-Regulation; Upper Extremity; Vertebral column; Work; analysis pipeline; arm paresis; blood oxygen level dependent; denoising; density; disability; experience; grasp; hand grasp; hemiparetic stroke; improved; indexing; innovation; insight; interest; mortality; motor control; motor deficit; motor function recovery; motor impairment; nerve injury; neural; neuroimaging; neuromechanism; neurovascular; neurovascular injury; novel; post stroke; reticulospinal tract; signal processing; stroke hemiparesis; success; synergism; targeted treatment

PROJECT SUMMARY/ABSTRACT Individuals with chronic hemiparetic stroke typically have significant upper extremity motor impairments. These impairments include “associated reactions” and abnormal “muscle synergies”, characterized by inter- and intra- limb muscle coactivation patterns, respectively. It has been postulated that these motor impairments are due to an upregulation of the contralesional cortico-reticulospinal tract (CRST), after stroke-inflicted damage to corticofugal pathways. Neuroimaging in the brain, including functional magnetic resonance imaging (fMRI) and electromyography (EMG) studies, have widely substantiated this hypothesis, while leaving a tangible gap between measures of cortical neural function and skeletal muscle coactivation patterns. To our knowledge, neural activity in the spinal cord has not been investigated in the context of post-stroke motor impairments. Therefore, it is critical to integrate advanced fMRI methods in the human spinal cord with EMG techniques to investigate an increased reliance on the CRST in chronic hemiparetic stroke. The objectives of this research proposal are to investigate the neural mechanisms of post-stroke motor impairment and long-term to inform development of more targeted therapeutic interventions. If upregulation of the CRST is responsible for force generation in the paretic upper extremity, its characteristic bilateral and unilateral projections would be expected to drive associated reactions when activating the non-paretic hand, and muscle synergies in the paretic limb when activating the paretic hand. Spinal cord fMRI can provide direct insight into neural activation and motor pathway use in the human cervical spinal cord. In the proposed project, participants will perform unilateral isometric hand-grasping tasks; muscle activation will be measured with EMG and spinal cord neural activity will be measured with fMRI. Aim 1 will investigate the relationship of associated reactions and the lateralization of spinal cord neural activity. CRST-driven associated reactions are expected to elicit increased inter-limb muscle coactivation and more bilateral spinal cord neural activation when performing the task with the non-paretic hand. Aim 2 will investigate the relationship of abnormal motor synergies and the longitudinal extent of motor activation. Synergies driven by diffuse unilateral CRST projections are expected to elicit increased intra-limb muscle coactivation and an increased longitudinal extent of spinal cord activation. To execute this research project, the applicant will gain expertise in the neuropathophysiology of stroke and EMG, receive mentorship from experts in neuroscience and magnetic resonance imaging, and train in scientific communication, mentorship, and leadership. Northwestern University’s collaborative medical campus, with neuroimaging experts and state-of-the art research-dedicated MRI scanners, fosters a complete environment for scientific training and innovative research. The novel implementation of advanced spinal cord fMRI techniques will inform our understanding and treatment of stereotypical movement patterns in chronic hemiparetic stroke.

项目概要/摘要 患有慢性偏瘫中风的个体通常有明显的上肢运动障碍。 损伤包括“相关反应”和异常的“肌肉协同作用”，其特征是内部和内部 据推测，这些运动障碍是由于肢体肌肉共激活模式造成的。 中风造成损伤后，对侧皮质网状脊髓束（CRST）上调 大脑的神经影像学，包括功能性磁共振成像（fMRI）和 肌电图（EMG）研究广泛证实了这一假设，同时留下了明显的空白 据我们所知，皮质神经功能和骨骼肌共激活模式的测量之间。 尚未在中风后运动障碍的背景下研究脊髓神经活动。 因此，将先进的人类脊髓功能磁共振成像方法与肌电图技术相结合至关重要 调查慢性偏瘫卒中对 CRST 的依赖性增加。 本研究计划的目的是研究中风后运动的神经机制 如果上调，则可以为开发更有针对性的治疗干预措施提供信息。 CRST 负责偏瘫上肢的力量产生，其特征是双侧和 当激活非麻痹手时，单边投射预计会驱动相关反应，并且 激活瘫痪手时瘫痪肢体的肌肉协同作用脊髓功能磁共振成像可以提供直接的洞察力。 在拟议的项目中，研究人员研究了人类颈脊髓的神经激活和运动通路的使用。 参与者将执行单侧等长抓握任务；将使用肌电图测量肌肉激活 脊髓神经活动将通过功能磁共振成像进行测量，目标 1 将研究相关关系。 预计 CRST 驱动的反应和脊髓神经活动的偏侧化。 表演时引起四肢间肌肉协同激活和更多双侧脊髓神经激活 目标 2 将调查异常运动协同与非麻痹手的关系。 运动激活的纵向范围预计由弥散性单侧 CRST 预测驱动。 引起肢体内肌肉共激活的增加和脊髓激活的纵向范围的增加。 为了执行该研究项目，申请人将获得中风和神经病理生理学方面的专业知识 EMG，接受神经科学和磁共振成像专家的指导，并接受科学培训 沟通、指导和领导力。 神经影像专家和最先进的研究专用 MRI 扫描仪，为 先进脊髓功能磁共振成像技术的科学培训和创新研究。 将有助于我们理解和治疗慢性偏瘫中风的典型运动模式。