Neurophysiological Evaluation of Training Effect on Cancer-Related Weakness

描述（由申请人提供）：虚弱限制了许多癌症幸存者的活动能力，降低了生活质量，特别是那些患有晚期癌症的人。早期的研究表明，高强度力量训练（HIST）对获得肌肉力量至关重要。虽然参加HIST对年轻和健康的人来说没有什么困难，但这种训练对许多身体能力有限的虚弱癌症幸存者来说是令人生畏和不安全的。然而，近年来的证据表明，高强度的训练（预期的肌肉收缩）结合没有或很少的体育锻炼可以通过增加大脑对肌肉的指挥来显着增强肌肉，这有助于提高运动单位的招募和激活水平。尽管高强度训练对肌肉强化的效果已经在健康的年轻人和老年人中得到了认可，但关于其在改善虚弱患者的力量方面的应用还一无所知，考虑到他们在参与这种训练时可能面临的困难，这些患者可能从参与这种类型的训练中受益最多。 此外，尚待确定高脑力训练诱导的力量增益现象背后的详细神经生理学机制。来自PI实验室的初步数据显示，虚弱的癌症患者经过高强度的运动想象训练可以显着提高他们的力量。基于EEG的运动相关皮层电位测量表明，这种训练后，目标肌肉的下行命令增强。这些观察结果导致我们的基本假设，即由神经适应引起的训练诱导的力量增益不依赖于肌肉锻炼的强度;相反，它主要依赖于训练期间的自愿努力水平，而不管体育锻炼强度如何。本研究的主要目标是通过训练弱癌症幸存者高强度加中等强度（HEMI）和低强度结合中等强度（LEMI）肌肉运动来测试这一假设，并评估训练后的力量改善和潜在的神经可塑性。该研究的目的是确定HEMI和LEMI训练对握力和基于fMRI的脑连接水平的影响，该脑连接调节下行命令和功能性脑肌肉耦合（fBMC）以获得最大肌肉力量。假设HEMI训练将显著增加力量并提高皮层网络连接和fBMC水平，但LEMI不会。研究结果将表明，HEMI训练是一种有效的方法，可以激发神经可塑性，促进乳腺癌幸存者的肌肉力量。虽然结果将从乳腺癌患者中获得，但该方法（HEMI训练）并不限于该患者人群进行自愿肌肉强化。

DESCRIPTION (provided by applicant): Weakness limits mobility and diminishes quality of life in many cancer survivors, especially in those who suffer from late stage of cancer. Early research suggests that high-intensity strength training (HIST) is essential to gain muscle strength. Although participating in HIST posts little difficulties for younger and healthy individuals, such training is intimidating and unsafe for many weak cancer survivors with limited physical abilities. Evidence in recent years, however, has shown that training with high effort (intended muscle contraction) combined with no or little physical exercise can significantly strengthen muscle by increasing brain-to-muscle command, which helps improve motor unit recruitment and activation level. Although the effect of high-effort training on muscle strengthening has been recognized in healthy young and older adults, nothing is known regarding its application to improving strength in weak patients, individuals who may benefit most from participating in this type of training, given difficulties they may face when engaging in conventional HIST. Further, detailed neurophysiological mechanisms behind the phenomenon of high mental effort training- induced strength gain are yet to be determined. Preliminary data from the PI's laboratory show that cancer patients with weakness undergone high-effort motor imagery training can significantly improve their strength. EEG-based movement-related cortical potential measurement demonstrates enhanced descending command to target muscle following such training. These observations led to our fundamental hypothesis that training-induced strength gain resulting from neural adaptations is not dependent on intensity of muscle exercise; rather, it relies primarily on the level of voluntary effort during training regardless o physical exercise intensity. The major goal of this study is to test this hypothesis by training weak cancer survivors with high effort plus moderate intensity (HEMI) and low effort combined with moderate intensity (LEMI) muscle exercises and evaluate strength improvement and underlying neural plasticity after training. The Aims of the study are to determine the effects of HEMI and LEMI training on handgrip strength and level of fMRI-based brain connectivity that modulates the descending command and functional brain-muscle coupling (fBMC) for maximal muscle force. It is hypothesized that the HEMI training will significantly gain strength and elevat the level of cortical network connectivity and fBMC but the LEMI will not. The findings will show that HEMI training is an effective approach to provoke neural plasticity that promotes muscle strength in breast cancer survivors with weakness. Although the results will be acquired from breast cancer patients, the method (HEMI training) is not limited to this patient population for voluntary muscle strengthening.