Modulation effects of epidural spinal cord stimulation on muscle activities during walking
Modulation effects of epidural spinal cord stimulation on muscle activities during walking
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DOI：
10.1109/tnsre.2005.862694
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发表时间：
2006-03-01
影响因子：
4.9
通讯作者：
Carhart, MR
中科院分区：
文献类型：
--
作者：
Huang, H;He, JP;Carhart, MR
据报道，硬膜外脊髓刺激（ESCS）联合部分负重治疗（PWBT）可促进慢性不完全性脊髓损伤（ISCI）后个体功能步行的恢复。本报告分析了肌肉活动，以研究ESCS对步态训练中肌肉恢复的调节作用。两名ISCI患者参与了这项研究，他们都被归类为ASIA C，下肢运动评分较低。刺激电极放置在T10-L2脊髓节段的硬膜外间隙，参与者1沿中线放置（S1），参与者2离中线放置（S2）。对跑步机步态中ESCS开、关两种状态下腿部肌肉的表面肌电图进行时频域分析。ESCS的应用对两名参与者的肌肉活动产生了急性调节，但观察到的肌电信号的模式、幅度和频谱内容不同。在SI中，与ESCS关闭时相比，ESCS诱导了肌肉活动的时间模式向正常方向的显著转变，尽管ESCS打开和关闭状态之间的频率分布没有引起明显的变化。当ESCS应用于S2时，观察到肌电强度的调节，从而改善了行走时的关节运动学。在这种情况下，时频分析中出现了刺激夹带。结果表明，ESCS激活脊髓背侧的神经结构，促进与步态相关的肌肉募集。ESCS的确切效果取决于电极的放置和可能的损伤历史和残余功能，但总的来说，ESCS对两种ISCI受试者的步行速度、耐力和努力感的改善都有积极的影响。
Epidural spinal cord stimulation (ESCS) combined with partial weight bearing therapy (PWBT) has been reported to facilitate recovery of functional walking for individuals after chronic incomplete spinal cord injury (ISCI). Muscle activities were analyzed in this report to examine the modulation effect of ESCS on muscle recruitment during gait training. Two ISCI individuals participated in the study and both are classified as ASIA C with low motor scores in the lower limbs. Stimulating electrodes were placed at the epidural space over T10-L2 spinal segments, along the midline in participant 1 (S1), and off-midline in participant 2 (S2). Surface electromyograms (EMGs) from leg muscles under both ESCS ON and OFF conditions recorded during treadmill gait were analyzed in time-frequency domains. ESCS application produced acute modulations in muscle activities in both participants, but the observed pattern, magnitude, and spectral content of the EMGs differed. In SI, ESCS induced a significant shift in the temporal pattern of muscle activity toward normal comparing with that when ESCS was OFF, though without eliciting noticeable change in frequency distribution between ESCS ON and OFF conditions. When ESCS was applied in S2, a modulation of EMG magnitude was observed and, consequently, improved joint kinematics during walking. In this case, a stimulation entrainment appeared in time-frequency analysis. The results suggest that ESCS activates neural structures in the dorsal aspect of the spinal cord and facilitates gait-related muscle recruitment. The exact effects of ESCS depend on the electrode placement and possibly injury history and residual functions, but in general ESCS produces a positive effect on improved walking speed, endurance, and reduced sense of effort in both ISCI subjects.