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.

项目摘要/摘要 患有慢性偏瘫中风的个体通常会有明显的上肢运动障碍。这些 障碍包括“相关反应”和异常“肌肉协同作用”，其特征是 肢体肌肉共激活模式。有人认为这些电动机障碍是由于 对比的皮质 - 续线界（CRST）的上调，造成了损害 皮质型途径。大脑中的神经影像学，包括功能磁共振成像（fMRI）和 肌电图（EMG）研究已广泛证实了这一假设，同时留下了切实的差距 在皮质神经元功能和骨骼肌共激活模式之间的测量之间。据我们所知， 脊髓中的神经活性尚未在中风后运动障碍的背景下进行研究。 因此，对于使用EMG技术在人脊髓中综合的高级fMRI方法至关重要 研究慢性偏瘫中风中CRST的保留率增加。 该研究建议的目标是研究中风后电动机的神经机制 障碍和长期为开发更有针对性的治疗干预措施的发展。如果上调 CRST负责在侧肢上肢，其特征双侧和 在激活非预性手时，单方面项目将推动相关反应，并且 激活偏心手时，肌肉在侧肢中的协同作用。脊髓fMRI可以提供直接见解 进入人颈脊髓中的神经激活和电动途径使用。在拟议的项目中 参与者将执行单方面的等距手工擦伤任务；将用EMG测量肌肉激活 通过fMRI测量脊髓神经活动。 AIM 1将调查关联的关系 反应和脊髓神经元活性的横向化。 CRST驱动的相关反应有望 表演时会增加肌间肌肉共激活和更多双侧脊髓神经激活 非少手的任务。 AIM 2将研究异常运动协同作用与 运动激活的纵向程度。预计由分散单方面CRST项目驱动的协同作用预计 引起肌肉内肌肉共激活增加，并增加脊髓激活的纵向程度。 为了执行该研究项目，申请人将获得中风神经病理生理学的专业知识 EMG，获得神经科学和磁共振成像专家的精神训练，并接受科学训练 沟通，心态和领导力。西北大学的合作医疗校园，与 神经影像学专家和最先进的研究专业的MRI扫描仪，促进了一个完整的环境 科学培训和创新研究。高级脊髓fMRI技术的新颖实现 将告知我们对慢性偏瘫中风中刻板印象运动模式的理解和治疗。