Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland.
Department of Neurology, University Hospital Zurich, Zurich, Switzerland.
J Neurotrauma. 2020 Nov 1;37(21):2302-2314. doi: 10.1089/neu.2020.7030. Epub 2020 Aug 10.
Locomotor recovery after incomplete spinal cord injury (iSCI) is influenced by spinal and supraspinal networks. Conventional clinical gait analysis fails to differentiate between these components. There is evidence that corticospinal control is enhanced during targeted walking, where each foot must be continuously placed on visual targets in randomized order. This study investigates the potential of targeted walking in the functional assessment of corticospinal integrity. Twenty-one controls and 16 individuals with chronic iSCI performed normal and targeted walking on a treadmill while electromyograms (EMGs) and kinematics were recorded. Precision (% of accurate foot placements) in targeted walking was significantly lower in individuals with iSCI (82.9 ± 14.7%, controls: 94.9 ± 4.0%). Although the overall kinematic pattern was comparable between walking conditions, controls showed significantly higher semitendinosus (ST) activity before heel-strike during targeted walking. This was accompanied by a shift of relative EMG intensity from 90-120 Hz to lower frequencies of 20-60 Hz, previously associated with corticospinal control of muscle activity. Targeted walking in individuals with iSCI evoked smaller EMG changes, suggesting that the switch to more corticospinal control is impaired. Accordingly, mildly impaired iSCI individuals revealed higher adaptations to the targeted walking task than more-impaired individuals. Recording of EMGs during targeted walking holds potential as a research tool to reveal further insights into the neuromuscular control of locomotion. It also complements findings of pre-clinical studies and is a promising novel surrogate marker of integrity of corticospinal control in individuals with iSCI and other neurological impairments. Future studies should investigate its potential for diagnosis or tracking recovery during rehabilitation.
不完全性脊髓损伤 (iSCI) 后的运动功能恢复受脊髓和脊髓上网络的影响。传统的临床步态分析无法区分这些成分。有证据表明，在目标行走中，皮质脊髓控制得到增强，其中每只脚必须连续踩到随机排列的视觉目标。本研究探讨了目标行走在皮质脊髓完整性功能评估中的潜在应用。21 名对照者和 16 名慢性 iSCI 患者在跑步机上进行正常和目标行走，同时记录肌电图 (EMG) 和运动学数据。目标行走的准确性 (准确放置脚的百分比) 在 iSCI 患者中显著降低（82.9±14.7%，对照组：94.9±4.0%）。尽管在行走条件下整体运动模式相似，但在目标行走中，对照组在脚跟触地前半腱肌 (ST) 的活动明显更高。这伴随着相对 EMG 强度从 90-120 Hz 转移到 20-60 Hz 的较低频率，这与皮质脊髓对肌肉活动的控制有关。iSCI 患者的目标行走引起的 EMG 变化较小，表明切换到更多皮质脊髓控制受损。因此，轻度受损的 iSCI 患者比受损更严重的患者对目标行走任务的适应能力更高。在目标行走期间记录 EMG 具有作为研究工具的潜力，可以更深入地了解运动的神经肌肉控制。它还补充了临床前研究的结果，是 iSCI 患者和其他神经功能障碍患者皮质脊髓控制完整性的有前途的新型替代标志物。未来的研究应探讨其在诊断或跟踪康复期间恢复的潜力。
