KITE-Toronto Rehabilitation Institute (G.B., C.P.S.), University Health Network, Toronto, ON, Canada.
Krembil Research Institute (G.B., C.P.S.), University Health Network, Toronto, ON, Canada.
Stroke. 2023 Aug;54(8):2156-2166. doi: 10.1161/STROKEAHA.123.043053. Epub 2023 Jul 13.
Stroke results in loss of upper motor neuron control over voluntary movements and emergence of abnormal synergies. Presently, it is unclear to what extent poststroke recovery reflects true recovery (restitution), compensation, or some combination of these processes. Here, we investigated this question using behavioral and kinematic analyses of skilled reaching in rats subjected to severe stroke that affected both the forelimb motor cortex and dorsolateral striatum.
After stroke, male rats either spontaneously recovered or received enriched rehabilitation. We assessed forelimb motor recovery using behavioral and kinematic outcome measures. To provide insights into the mechanisms underlying the effects of rehabilitation on behavior, we used intracortical microstimulation and FosB (protein fosB) immunostaining techniques.
Enriched rehabilitation significantly improved food pellet retrieval in the staircase-reaching task. Rehabilitation resulted in several poststroke flexion synergies returning to prestroke patterns, and across subjects, these changes correlated with the intensity of rehabilitation. Enriched rehabilitation increased the proportion of distal movement representation in the perilesional cortex and increased use-dependent activation in the ipsilesional red nucleus.
These results provide evidence that enriched rehabilitation enhances recovery, at least in part, by restitution of forelimb function following severe stroke. Furthermore, the restitution of function is associated with changes in multiple motor-related structures at different levels of the central nervous system. A better understanding of the processes that underlie improved motor performance, along with the identification of midbrain circuits activated by rehabilitation, represent new insights and potential targets for optimizing poststroke recovery.
中风会导致上运动神经元对随意运动的控制丧失，并出现异常协同作用。目前，尚不清楚中风后恢复在多大程度上反映了真正的恢复（恢复）、代偿还是这些过程的某种组合。在这里，我们使用严重影响前肢运动皮层和背外侧纹状体的大鼠熟练伸手行为和运动学分析来研究这个问题。
中风后，雄性大鼠要么自发恢复，要么接受丰富的康复治疗。我们使用行为和运动学结果测量来评估前肢运动恢复情况。为了深入了解康复对行为的影响机制，我们使用了皮质内微刺激和 FosB（蛋白 fosB）免疫染色技术。
丰富的康复治疗显著改善了在阶梯式取食任务中对食物颗粒的取回。康复治疗导致几个中风后屈肌协同作用恢复到中风前的模式，并且在不同的个体中，这些变化与康复治疗的强度相关。丰富的康复治疗增加了损伤皮层内的远端运动代表比例，并增加了同侧红核的使用依赖性激活。
这些结果提供了证据表明，丰富的康复治疗至少部分通过严重中风后的前肢功能恢复来增强恢复。此外，功能的恢复与中枢神经系统不同水平的多个运动相关结构的变化有关。更好地理解改善运动表现的过程，以及识别康复激活的中脑回路，代表了新的见解和优化中风后恢复的潜在目标。
