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Determination of the Recruitment of Indirect Motor Pathways in Chronic Hemiparetic Stroke

慢性偏瘫中风间接运动通路募集的测定

基本信息

批准号：
9978864
负责人：
JULIUS P DEWALD
金额：
$ 22.76万
依托单位：
NORTHWESTERN UNIVERSITY AT CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-07-16 至 2023-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9978864
关键词：
Activities of Daily Living Affect Behavior Biological Markers Brain Brain Injuries Brain Stem Chronic Clinical Contralateral Corticospinal Tracts Coupling Development Distant Elbow Elbow joint structure Electroencephalography Evaluation Extensor Fingers Flexor Frequencies Future Generations Goals Hand Hand functions Handedness Hyperactive behavior Impairment Individual Interruption Intervention Joints Knowledge Lead Lesion Lifting Link Measures Mechanics Methods Motor Motor Cortex Motor Pathways Movement Muscle Neural Pathways Neuronal Plasticity Neurons Oligonucleotides Paresis Participant Pathway interactions Positioning Attribute Recovery Reflex action Rehabilitation therapy Reporting Research Research Personnel Shapes Shoulder Sigmoid colon Signal Transduction Stretching Stroke Synapses Synaptic Transmission System Testing Time Torque Upper Extremity Weight Lifting Wrist abnormal reflex arm arm function arm paresis base clinical practice combat functional disability hemiparetic stroke improved indexing innovation models and simulation motor impairment motor recovery neural model neuromechanism novel novel therapeutic intervention post stroke recruit relating to nervous system spasticity stretch reflex stroke recovery stroke rehabilitation synergism

项目摘要

Abstract. Motor impairments post-stroke, such as the upper limb flexion synergy and abnormal stretch reflexes, greatly affect an individual’s ability to implement activities of daily living. Despite the development of various clinical interventions for motor recovery after stroke, rehabilitation treatments, especially in more impaired individuals, are only minimally effective. This is due to: 1) many remaining gaps in our understanding of specific mechanisms underlying motor impairments post stroke that inform clinical practice, and 2) lack of sensitive biomarkers to determine the neuroplasticity resulting from interruptions of neural pathways caused by the stroke and during recovery. Our long-term goal is to develop a sensitive way to quantitatively assess the lesion-induced utilization of remaining motor pathways post stroke, which would allow better examination of stroke recovery and evaluation of rehabilitation interventions. Our previous studies indicate that motor impairments post hemiparetic stroke are likely caused by an increased reliance on contralesional indirect motor pathways via the brainstem, following stroke-induced losses of ipsilesional corticospinal projections. Thus, the objective of this proposal is to quantitatively determine the usage of indirect motor pathways and its link to the expression of the flexion synergy and abnormal stretch reflexes, by examining changes in neural connectivity of motor pathways as a function of shoulder abduction (SABD) load. In contrast to the direct corticospinal tract, these indirect pathways contain more synapses, which thus may cause an enhanced nonlinear neural connectivity via the motor pathways due to the nonlinear sigmoid shape of synaptic behavior and its cumulative effect across synapses. Thus, our central hypotheses are that: 1) an increased usage of indirect motor pathways while lifting the paretic arm, requiring SABD and causing the flexion synergy, will lead to enhanced nonlinear connectivity between brain and muscle activity; 2) the recruitment of indirect motor pathways will also affect the stretch reflex, in particular, its transcortical reflex component, resulting in increased nonlinear connectivity between stretch perturbations and muscle activity. Finally, these indirect pathways may prolong the neural transmission delay in the transcortical reflex loop, resulting in an increased time lag between perturbations and muscle activity. Using our recently developed nonlinear connectivity method and mechanically well-controlled experimental paradigms, we aim to test these hypotheses by: 1) comparing linear vs. nonlinear connectivity between brain and muscle activity during the generation of different levels of SABD torque in individuals post hemiparetic stroke; 2) quantifying changes of nonlinear connectivity and time delay of the stretch reflex post-stroke as a function of SABD torque level. As such, this project will provide new sensitive biomarkers that determine the recruitment of indirect motor pathways resulting in functional disability of upper extremity post hemiparetic stroke. This will also lead to a better understanding of neural mechanisms underlying stroke-induced motor impairments that inform clinical practice to combat the flexion synergy and associated hyperactive stretch reflexes following a unilateral brain injury.

摘要。中风后的运动损伤，如上肢屈曲协同作用和异常的拉伸反射，