Reduction of common synaptic drive to ankle dorsiflexor motoneurons during walking in patients with spinal cord lesion
Reduction of common synaptic drive to ankle dorsiflexor motoneurons during walking in patients with spinal cord lesion
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DOI：
10.1152/jn.00082.2005
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发表时间：
2005-08-01
影响因子：
2.5
通讯作者：
Nielsen, JB
中科院分区：
文献类型：
--
作者：
Hansen, NL;Conway, BA;Nielsen, JB
通过分析运动单位的时域和频域耦合，有可能获得有关行走过程中运动神经元突触驱动的信息。本研究的目的是比较健康受试者和脊髓不完全损伤患者在行走过程中的运动单位耦合，以获得损伤导致运动神经元驱动差异的证据。这些信息对于步态恢复的新策略的开发是重要的。20例不完全性脊髓损伤（SCL）患者参加了研究。在11名健康受试者中进行对照实验。在所有健康受试者中，在跑步机行走的摆动阶段，胫骨前肌（TA）运动单位的放电存在明显的短期同步性。这是确定从一个狭窄的中央峰的存在下，累积量密度从成对的EMG记录和这些信号之间的存在下，在10至20赫兹频带的显着的相干性。这种短期同步性的指标在患者组中要么不存在，要么非常小。短期同步性的数量和10- 20- Hz的相干性在患者的幅度之间的关系进行了讨论，与步态能力。这表明，在健康受试者行走过程中，对脊髓的脊髓上驱动负责10- 20- Hz频带中的短期同步性和连贯性。这些功能的缺失或减少可能是SCL患者脊髓上步态控制受损的生理标志。此类标记物可能对中枢运动损伤患者的运动恢复具有诊断和预后价值。
It is possible to obtain information about the synaptic drive to motoneurons during walking by analyzing motor- unit coupling in the time and frequency domains. The purpose of the present study was to compare motor- unit coupling during walking in healthy subjects and patients with incomplete spinal cord lesion to obtain evidence of differences in the motoneuronal drive that result from the lesion. Such information is of importance for development of new strategies for gait restoration. Twenty patients with incomplete spinal cord lesion ( SCL) participated in the study. Control experiments were performed in 11 healthy subjects. In all healthy subjects, short- term synchronization was evident in the discharge of tibialis anterior ( TA) motor units during the swing phase of treadmill walking. This was identified from the presence of a narrow central peak in cumulant densities constructed from paired EMG recordings and from the presence of significant coherence between these signals in the 10- to 20- Hz band. Such indicators of short- term synchrony were either absent or very small in the patient group. The relationship between the amount of short- term synchrony and the magnitude of the 10- to 20- Hz coherence in the patients is discussed in relation to gait ability. It is suggested that supraspinal drive to the spinal cord is responsible for short- term synchrony and coherence in the 10- to 20- Hz frequency band during walking in healthy subjects. Absence or reduction of these features may serve as physiological markers of impaired supraspinal control of gait in SCL patients. Such markers could have diagnostic and prognostic value in relation to the recovery of locomotion in patients with central motor lesions.