Improved isometric force endurance after transcranial direct current stimulation over the human motor cortical areas
Improved isometric force endurance after transcranial direct current stimulation over the human motor cortical areas
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DOI：
10.1111/j.1460-9568.2007.05633.x
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发表时间：
2007-07-01
影响因子：
3.4
通讯作者：
Priori, A.
中科院分区：
文献类型：
--
作者：
Cogiamanian, F.;Marceglia, S.;Priori, A.
神经肌肉疲劳是肌肉纤维产生力的能力的运动依赖性下降。为了研究经颅直流电刺激（tDCS; 1.5 mA，10 min，0.026 C/cm 2）对大脑兴奋性的调控是否能调节神经肌肉疲劳，我们评估了健康受试者大脑皮质右侧运动区的大脑极化对左肘屈肌次最大等长收缩耐力时间的影响。在24名健康志愿者中，研究方案包括在脑极化之前和之后立即评估左肘屈肌的最大自主收缩（MVC）和疲劳等长收缩（MVC的35%）。基线（T0）和调节后（T1）评价之间间隔1小时。tDCS后，MVC与基线相比保持不变（平均值± SEM;阳极tDCS：T0，154.4 ± 18.07; T1，142.8 ± 16.62 N;阴极tDCS：T0，156 ± 18.75; T1，141.86 ± 17.53 N;对照：T0，148.8 ± 6.64; T1，137.6 ± 7.36 N; P > 0.1）。相反，阳极tDCS或无刺激后，耐受时间的减少显著小于阴极tDCS或无刺激后（分别为-21.1 +/-5.5%、-35.7 +/- 3.3%和-39.3 +/-3.3%; P < 0.05）。在tDCS后，评价的肌电图变量均未发生变化。阳极tDCS可以通过直接调节运动皮层兴奋性，调节运动前区，减少疲劳相关的肌肉疼痛，增加动力和改善背肌耦合来改善耐力时间。我们的研究结果表明，大脑皮层运动区的阳极tDCS可以改善肌肉耐力，为在正常（即运动医学）和病理条件下增加肌肉耐力和减少肌肉疲劳开辟了道路。
Neuromuscular fatigue is the exercise-dependent decrease in the ability of muscle fibres to generate force. To investigate whether manipulation of brain excitability by transcranial direct current stimulation (tDCS; 1.5 mA, 10 min, 0.026 C/cm(2)) modulates neuromuscular fatigue, we evaluated the effect of brain polarization over the right motor areas of the cerebral cortex of healthy subjects on the endurance time for a submaximal isometric contraction of left elbow flexors. In 24 healthy volunteers the study protocol comprised an assessment of the maximum voluntary contraction (MVC) for the left elbow flexors and a fatiguing isometric contraction (35% of MVC), before and immediately after brain polarization. One hour elapsed between baseline (T0) and postconditioning (T1) evaluation. After tDCS, MVC remained unchanged from baseline (mean +/- SEM; anodal tDCS: T0, 154.4 +/- 18.07; T1, 142.8 +/- 16.62 N; cathodal tDCS: T0, 156 +/- 18.75; T1, 141.86 +/- 17.53 N; controls: T0, 148.8 +/- 6.64; T1, 137.6 +/- 7.36 N; P > 0.1). Conversely, endurance time decreased significantly less after anodal than after cathodal tDCS or no stimulation (-21.1 +/- 5.5%, -35.7 +/- 3.3% and -39.3 +/- 3.3%, respectively; P < 0.05). None of the evaluated electromyographic variables changed after tDCS. Anodal tDCS could improve endurance time by directly modulating motor cortical excitability, modulating premotor areas, decreasing fatigue-related muscle pain, increasing motivation and improving synergist muscle coupling. Our findings, showing that anodal tDCS over the motor areas of the cerebral cortex improves muscle endurance, open the way to increasing muscle endurance and decreasing muscle fatigue in normal (i.e. sports medicine) and pathological conditions.