Neige Cécilia, Lebon Florent, Mercier Catherine, Gaveau Jérémie, Papaxanthis Charalambos, Ruffino Célia
Cereb Cortex. 2022 Jan 22;32(3):640-651. doi: 10.1093/cercor/bhab246.
Pain influences both motor behavior and neuroplastic adaptations induced by physical training. Motor imagery (MI) is a promising method to recover motor functions, for instance in clinical populations with limited endurance or concomitant pain. However, the influence of pain on the MI processes is not well established. This study investigated whether acute experimental pain could modulate corticospinal excitability assessed at rest and during MI (Exp. 1) and limit the use-dependent plasticity induced by MI practice (Exp. 2). Participants imagined thumb movements without pain or with painful electrical stimulations applied either on digit V or over the knee. We used transcranial magnetic stimulation to measure corticospinal excitability at rest and during MI (Exp. 1) and to evoke involuntary thumb movements before and after MI practice (Exp. 2). Regardless of its location, pain prevented the increase of corticospinal excitability that is classically observed during MI. In addition, pain blocked use-dependent plasticity following MI practice, as testified by a lack of significant posttraining deviations. These findings suggest that pain interferes with MI processes, preventing the corticospinal excitability facilitation needed to induce use-dependent plasticity. Pain should be carefully considered for rehabilitation programs using MI to restore motor function.
疼痛会影响运动行为以及体育锻炼所引发的神经可塑性适应。运动想象（MI）是一种恢复运动功能的有效方法，例如对于耐力有限或伴有疼痛的临床患者群体。然而，疼痛对运动想象过程的影响尚未明确。本研究调查了急性实验性疼痛是否会调节静息状态和运动想象期间评估的皮质脊髓兴奋性（实验1），以及是否会限制运动想象练习所诱导的使用依赖性可塑性（实验2）。参与者在无疼痛或在手指V或膝盖上施加疼痛性电刺激的情况下想象拇指运动。我们使用经颅磁刺激来测量静息状态和运动想象期间的皮质脊髓兴奋性（实验1），并在运动想象练习前后诱发不自主拇指运动（实验2）。无论疼痛位置如何，它都会阻止在运动想象期间通常观察到的皮质脊髓兴奋性增加。此外，疼痛会阻碍运动想象练习后的使用依赖性可塑性，这表现为训练后没有显著偏差。这些发现表明，疼痛会干扰运动想象过程，阻止诱导使用依赖性可塑性所需的皮质脊髓兴奋性促进。对于使用运动想象来恢复运动功能的康复计划，应谨慎考虑疼痛因素。
