1 University of Ottawa, Ottawa, ON, Canada.
2 Canadian Partnership for Stroke Recovery, Ottawa, ON, Canada.
Neurorehabil Neural Repair. 2018 Jan;32(1):3-6. doi: 10.1177/1545968317751210. Epub 2018 Jan 10.
In human upper-limb stroke, initial level of functional impairment or corticospinal tract injury can accurately predict the degree of poststroke recovery, independent of rehabilitation practices. This proportional recovery rule implies that current rehabilitation practices may play little or no role in brain repair, with recovery largely a result of spontaneous biological recovery processes.
The present study sought to determine if similar biomarkers predict recovery of poststroke function in rats, indicating that an endogenous biological recovery process might be preserved across mammalian species.
Using a cohort of 593 male Sprague-Dawley rats, we predicted poststroke change in pellet retrieval in the Montoya staircase-reaching task based on initial impairment alone. Stratification of the sample into "fitters" and "nonfitters" of the proportional recovery rule using hierarchical cluster analysis allowed identification of distinguishing characteristics of these subgroups.
Approximately 30% of subjects were identified as fitters of the rule. These rats showed recovery in proportion to their initial level of impairment of 66% (95% CI = 62%-70%). This interval overlaps with those of multiple human clinical trials. A number of variables, including less severe infarct volumes and initial poststroke impairments distinguished fitters of the rule from nonfitters.
These findings suggest that proportional recovery is a cross-species phenomenon that can be used to uncover biological mechanisms contributing to stroke recovery.
在上肢中风患者中，初始功能障碍程度或皮质脊髓束损伤程度可准确预测中风后的恢复程度，而不受康复实践的影响。这种比例性恢复规律表明，目前的康复实践可能在脑修复中作用甚微，而恢复主要是自发的生物恢复过程的结果。
本研究旨在确定是否存在类似的生物标志物可预测大鼠中风后功能的恢复，这表明内源性生物恢复过程可能在哺乳动物物种中得以保留。
使用 593 只雄性 Sprague-Dawley 大鼠的队列，我们仅根据初始损伤来预测在 Montoya 阶梯式抓取任务中颗粒取回的卒中后变化。使用层次聚类分析对样本进行分层，将符合或不符合比例恢复规律的个体进行分组，以确定这些亚组的特征。
约 30%的研究对象被确定为符合该规律的个体。这些大鼠的恢复程度与其初始损伤程度成正比，达到 66%（95%CI=62%-70%）。这个区间与多项人类临床试验的结果相重叠。一些变量，包括梗死体积较小和初始卒中后损伤程度，可将符合规律的个体与不符合规律的个体区分开来。
这些发现表明，比例性恢复是一种跨物种现象，可以用于揭示促进中风恢复的生物学机制。
