Department of Health and Exercise Science, Appalachian State University, Boone, NC.
Med Sci Sports Exerc. 2020 Feb;52(2):335-344. doi: 10.1249/MSS.0000000000002129.
Given maladaptive neuroplasticity after musculoskeletal injury, interventions capable of restoring corticospinal excitability should be considered. We therefore aimed to determine if a 4-wk intervention of anodal transcranial direct current stimulation (aTDCS) with eccentric exercise would improve neural excitability, functional performance, and patient-reported function in individuals with chronic ankle instability (CAI).
Twenty-six individuals with CAI were recruited to undergo 4 wk of eccentric evertor strengthening. Subjects were randomized into aTDCS (n = 13) and sham (n = 13) groups, where the aTDCS group received 18 min of aTDCS (1.5 mA) over the primary motor cortex. Participants were assessed for cortical excitability, dynamic balance, muscle activation, functional performance, strength, and patient-reported function at baseline, week 2, week 4, and week 6.
Twenty-two subjects completed the training and test sessions. Cortical excitability (resting motor threshold) to peroneus longus in aTDCS increased from baseline (36.92 ± 11.53) to week 6 (32.91 ± 12.33, P = 0.024), whereas sham increased excitability from baseline (36.67 ± 12.74) to week 2 (27.86 ± 14.69, P = 0.007), but decreased at week 4 (35.63 ± 13.10, P = 0.022) and week 6 (35.99 ± 13.52, P = 0.006). Dynamic balance and muscle activation also improved in the aTDCS group from baseline to week 6 (P = 0.034). Functional performance on a side-hop test increased in all participants from baseline to week 2 (P = 0.003). The aTDCS group had decreased perceived disablement from week 2 (18.09 ± 6.41) to week 4 (15.55 ± 4.82, P = 0.046), whereas the sham group reported increased disablement from baseline (17.91 ± 4.59) to week 2 (21.00 ± 8.52, P = 0.047).
Our results provide preliminary evidence that 4 wk of eccentric training with aTDCS improves cortical excitability, functional performance, and patient-reported function in individuals with CAI. These data are the first to show the efficacy of noninvasive brain stimulation therapies in patients with musculoskeletal injury, and demonstrate the link between improved neural excitability and functional outcomes.
鉴于肌肉骨骼损伤后的适应不良神经可塑性，应考虑使用能够恢复皮质脊髓兴奋性的干预措施。因此，我们旨在确定 4 周的经颅直流电刺激（tDCS）与离心运动相结合的干预措施是否会改善慢性踝关节不稳定（CAI）患者的神经兴奋性、功能表现和患者报告的功能。
招募了 26 名患有 CAI 的参与者进行 4 周的离心外展肌强化训练。受试者被随机分为 tDCS 组（n = 13）和假刺激组（n = 13），其中 tDCS 组接受 18 分钟的初级运动皮层 1.5 mA 的 tDCS。在基线、第 2 周、第 4 周和第 6 周评估皮质兴奋性、动态平衡、肌肉激活、功能表现、力量和患者报告的功能。
22 名受试者完成了训练和测试。tDCS 组的腓骨长肌皮质兴奋性（静息运动阈值）从基线时的 36.92 ± 11.53 增加到第 6 周时的 32.91 ± 12.33（P = 0.024），而假刺激组从基线时的 36.67 ± 12.74 增加到第 2 周时的 27.86 ± 14.69（P = 0.007），但在第 4 周（P = 0.022）和第 6 周（P = 0.006）时降低。从基线到第 6 周，tDCS 组的动态平衡和肌肉激活也得到了改善（P = 0.034）。所有参与者的侧跳测试的功能表现均从基线增加到第 2 周（P = 0.003）。从第 2 周（18.09 ± 6.41）到第 4 周（15.55 ± 4.82，P = 0.046），tDCS 组的感知残疾程度降低，而假刺激组从基线时的 17.91 ± 4.59 增加到第 2 周（21.00 ± 8.52，P = 0.047）。
我们的结果初步表明，4 周的离心训练加 tDCS 可改善 CAI 患者的皮质兴奋性、功能表现和患者报告的功能。这些数据首次表明，非侵入性脑刺激疗法在肌肉骨骼损伤患者中具有疗效，并证明了神经兴奋性改善与功能结果之间的联系。
