School of Science and Health, Western Sydney University, Sydney, New South Wales, Australia.
Faculty of Health, University of Canberra, Canberra, Australian Capital Territory, Australia.
Pain. 2019 Nov;160(11):2624-2633. doi: 10.1097/j.pain.0000000000001656.
Repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex (M1) is increasingly being investigated as a means of alleviating chronic pain. However, rTMS interventions are typically initiated once pain has already become chronic and maladaptive patterns of neural activity are likely to have been established. A critical question is whether M1 rTMS applied soon after pain onset can prevent the development of maladaptive neural activity and promote recovery. This study investigated the effect of 5 consecutive days of excitatory M1 rTMS on pain, functional limitation, mechanical hyperalgesia, descending inhibitory pain control, and M1 organisation in the transition from acute to sustained pain. Thirty healthy participants attended 8 sessions over a 16-day period. On days 0, 2, and 4, nerve growth factor was injected into the right forearm to induce progressively developing muscle soreness and mechanical hyperalgesia. Active or sham excitatory rTMS was delivered on days 4 to 8. Clinical and neurophysiological outcomes were recorded on days 0, 2, 4, 6, 8, 11, and 14. Active rTMS promoted recovery of muscle soreness, pain, and mechanical hyperalgesia when compared with sham rTMS (all between-group P < 0.05). Corticomotor excitability and descending inhibitory pain control did not differ between groups. These findings suggest that active excitatory M1 rTMS promotes recovery of muscle soreness, pain, and mechanical hyperalgesia in the transition from acute to sustained experimental pain. The analgesic effects of M1 rTMS do not seem to be modulated by descending inhibitory pain control or local changes in corticomotor excitability.
重复经颅磁刺激（rTMS）刺激初级运动皮层（M1）越来越多地被研究作为缓解慢性疼痛的一种手段。然而，rTMS 干预通常在疼痛已经变为慢性和神经活动的适应不良模式已经建立后才开始。一个关键问题是，M1 rTMS 在疼痛发作后不久应用是否可以预防适应不良的神经活动并促进恢复。本研究调查了连续 5 天的兴奋性 M1 rTMS 对从急性到持续性疼痛过渡中疼痛、功能受限、机械性痛觉过敏、下行抑制性疼痛控制和 M1 组织的影响。30 名健康参与者在 16 天内参加了 8 次会议。在第 0、2 和 4 天，将神经生长因子注入右臂以引起逐渐发展的肌肉酸痛和机械性痛觉过敏。在第 4 至 8 天，给予活性或假兴奋性 rTMS。在第 0、2、4、6、8、11 和 14 天记录临床和神经生理结果。与假 rTMS 相比，活性 rTMS 促进了肌肉酸痛、疼痛和机械性痛觉过敏的恢复（所有组间 P < 0.05）。皮质运动兴奋性和下行抑制性疼痛控制在组间没有差异。这些发现表明，活性兴奋性 M1 rTMS 促进了从急性到持续性实验性疼痛过渡中肌肉酸痛、疼痛和机械性痛觉过敏的恢复。M1 rTMS 的镇痛效果似乎不受下行抑制性疼痛控制或皮质运动兴奋性的局部变化调节。
