McGovern Institute for Brain Research and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Proc Natl Acad Sci U S A. 2012 Sep 4;109(36):14652-6. doi: 10.1073/pnas.1212056109. Epub 2012 Aug 20.
The experimental findings herein reported are aimed at gaining a perspective on the complex neural events that follow lesions of the motor cortical areas. Cortical damage, whether by trauma or stroke, interferes with the flow of descending signals to the modular interneuronal structures of the spinal cord. These spinal modules subserve normal motor behaviors by activating groups of muscles as individual units (muscle synergies). Damage to the motor cortical areas disrupts the orchestration of the modules, resulting in abnormal movements. To gain insights into this complex process, we recorded myoelectric signals from multiple upper-limb muscles in subjects with cortical lesions. We used a factorization algorithm to identify the muscle synergies. Our factorization analysis revealed, in a quantitative way, three distinct patterns of muscle coordination-including preservation, merging, and fractionation of muscle synergies-that reflect the multiple neural responses that occur after cortical damage. These patterns varied as a function of both the severity of functional impairment and the temporal distance from stroke onset. We think these muscle-synergy patterns can be used as physiological markers of the status of any patient with stroke or trauma, thereby guiding the development of different rehabilitation approaches, as well as future physiological experiments for a further understanding of postinjury mechanisms of motor control and recovery.
本研究旨在深入了解大脑皮质区损伤后的复杂神经事件。皮质损伤（无论是创伤还是中风引起的）会干扰下行信号流向脊髓的模块化中间神经元结构。这些脊髓模块通过激活单个肌肉群（肌肉协同作用）来实现正常的运动行为。皮质损伤会破坏模块的协调，导致运动异常。为了深入了解这一复杂过程，我们对皮质损伤患者的多个上肢肌肉进行了肌电信号记录。我们使用因式分解算法来识别肌肉协同作用。我们的因式分解分析以定量的方式揭示了三种不同的肌肉协调模式，包括肌肉协同作用的保留、合并和分裂，这些模式反映了皮质损伤后发生的多种神经反应。这些模式随功能损伤的严重程度和中风发作后的时间间隔而变化。我们认为这些肌肉协同模式可以作为中风或创伤患者任何特定状态的生理标志物，从而指导不同康复方法的发展，以及进一步了解运动控制和恢复的损伤后机制的未来生理实验。
