StretchfMRI: a new technique to study the brainstem correlates of long-latency responses

项目总结 痉挛是中风后的一种常见情况。在临床上，痉挛可以被认为是一种速度相关的 伸展反射增加，是慢性病患者运动障碍的主要来源之一 卒中。虽然许多研究已经解决了痉挛如何调节短潜伏期反射的增益， 对调节长潜伏期反应的神经通路知之甚少，这是一种基本的 人类运动控制系统的组成部分，在中风后痉挛患者中受到严重影响。 在这个项目中，我们将开发StretchfMRI，这是一种新的测量技术，它结合了与MRI兼容的 具有肌肉肌电和通过功能磁共振成像对脑干进行高分辨率功能成像的机器人。 StretchfMRI将首次在活体和人类中实现对脑干核团活动的测量 在长延迟响应期间。在这个项目中，我们将使用StretchfMRI来建立 网状结构中的核产生长潜伏期反应。 这个项目中开发的技术是朝着定量理解基础知识迈出的重要一步 神经肌肉控制原理，并在评估神经运动障碍和 中风后的康复。StretchfMRI为建立皮质网功能的因果关系奠定了基础 与LLR关联。在未来的工作中，我们计划在患者群体中应用StretchfMRI来研究神经 与中风引起的运动障碍患者的强调痉挛相关。

PROJECT SUMMARY Spasticity is a common condition after stroke. Clinically, spasticity can be recognized as a velocity-dependent increase in stretch reflexes, and is one of the primary sources of motor impairment in individuals with chronic stroke. While a lot of research has addressed how spasticity modulates the gain of short-latency reflexes, much less is known about the neural pathways that regulate the long-latency responses, a fundamental component of the human motor control system that is severely affected in patients with post-stroke spasticity. In this project, we will develp StretchfMRI, a new measurement technique that combines an MRI-compatible robot with muscle electromyography and with high-resolution functional imaging of the brainstem via fMRI. StretchfMRI will enable, for the first time in vivo and in human, the measurement of activity of brainstem nuclei during long-latency responses. In this project, we will use StretchfMRI to establish the direct involvement of nuclei in the reticular formation in producing a long-latency response. The technique developed in this project is an important step towards a quantitative understanding of basic principles of neuromuscular control, and has important applications in assessing neuromotor impairment and recovery after stroke. StretchfMRI lays the groundwork for establishing causality in cortico-reticular function associated with LLRs. In future work, we plan to apply StretchfMRI in a patient population to study the neural correlates underscoring spasticity in patients with stroke-induced motor impairment.