Reduced functional recovery by delaying motor training after spinal cord injury
Reduced functional recovery by delaying motor training after spinal cord injury
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DOI：
10.1152/jn.00975.2004
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发表时间：
2005-07-01
影响因子：
2.5
通讯作者：
Gorassini, MA
中科院分区：
文献类型：
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作者：
Norrie, BA;Nevett-Duchcherer, JM;Gorassini, MA
本研究的目的是检查脊髓损伤后康复运动训练的延迟是否会影响功能性运动恢复。我们研究了一项熟练的运动任务，其中老鼠穿过升高的水平梯子，并量化了准确迈步的误差，即脚在梯级之间滑动。在胸椎 (T-8) 脊髓背侧象限损伤，旨在单方面切断皮质脊髓束和红核脊髓束后，在损伤后立即或延迟 3 个月后，重新训练大鼠走过梯子。训练前，立即训练的动物（69.4 +/- 5.3%）和延迟训练的动物（62.7 +/- 4.1%；平均值+/- SE）的受影响后肢准确迈步的错误率相似（没有显着差异），这表明如果大鼠不接触梯子，准确迈步不会自发改善。经过 3 周的训练课程（每天 30 次跨梯子，每周 5 天），如果在受伤后立即进行训练，准确的踏步表现会得到更大的改善。平均而言，立即训练的动物将迈步性能提高了 61.5 +/- 28.2%，而延迟训练组仅提高了 34.9 +/- 28.8%（显着不同）。两组动物的皮质脊髓束和红核脊髓束的损伤程度非常相似，表明损伤大小的差异不会导致性能改善的差异。皮质脊髓束和红核脊髓束有大损伤的动物（>70%）表现出训练后恢复较差（特别是延迟训练的动物），表明这两条途径对于调节准确步进的改善很重要。此外，鉴于反射恢复的时间过程与准确迈步的恢复时间过程无关，类迈步反射的恢复似乎对准确迈步的恢复没有贡献。我们的结论是，在部分脊髓损伤后立即开始训练依赖于下降控制的熟练运动任务会更有益。
The purpose of this study was to examine if a delay in rehabilitative motor training after spinal cord injury affects functional motor recovery. We studied a skilled motor task in which rats traversed a raised horizontal ladder and we quantified errors in accurate stepping, i.e., foot slips between rungs. After lesions to the dorsal quadrant of the thoracic (T-8) spinal cord that aimed to unilaterally sever the corticospinal and rubrospinal tracts, rats were re-trained to walk across the ladder, either immediately after injury or after a 3-mo delay. Before training, the error rate in accurate stepping of the affected hindlimb was similar in the immediately (69.4 +/- 5.3%) and delay (62.7 +/- 4.1%; means +/- SE)-trained animals (not significantly different), suggesting that accurate stepping did not improve spontaneously if rats were not exposed to the ladder. After a 3-wk course of training (30 runs across the ladder per day, 5 day/wk), improvements in accurate stepping performance were greater if training was implemented immediately after injury. On average, immediately trained animals improved stepping performance by 61.5 +/- 28.2%, whereas the delay trained group improved by only 34.9 +/- 28.8% (significantly different). The degree of damage to the corticospinal and rubrospinal tracts was very similar in the two groups of animals, indicating that differences in lesion size did not contribute to the differences in performance improvement. Animals with large lesions to the corticospinal and rubrospinal tracts (>70%) displayed poor recovery from training (especially for delay-trained animals), suggesting that these two pathways were important in mediating improvements in accurate stepping. In addition, recovery of stepping-like reflexes appeared not to contribute to the recovery of accurate stepping given that the time course of reflex recovery was not related to the time course of recovery of accurate stepping. We conclude that training of a skilled motor task that relies on descending control is more beneficial when initiated immediately after a partial spinal cord injury.