In 2008, it was proposed that the magnitude of recovery from nonsevere upper limb motor impairment over the first 3 to 6 months after stroke, measured with the Fugl-Meyer Assessment (FMA), is approximately 0.7 times the initial impairment (“proportional recovery”). In contrast to patients with nonsevere hemiparesis, about 30% of patients with an initial severe paresis do not show such recovery (“nonrecoverers”). Hence it was suggested that the proportional recovery rule (PRR) was a manifestation of a spontaneous mechanism that is present in all patients with mild-to-moderate paresis but only in some with severe paresis. Since the introduction of the PRR, it has subsequently been applied to other motor and nonmotor impairments. This more general investigation of the PRR has led to inconsistencies in its formulation and application, making it difficult to draw conclusions across studies and precipitating some cogent criticism. Here, we conduct a detailed comparison of the different studies reporting proportional recovery and, where appropriate, critique statistical methodology. On balance, we conclude that existing data in aggregate are largely consistent with the PRR as a population-level model for upper limb motor recovery; recent reports of its demise are exaggerated, as these excessively focus on the less conclusive issue of individual subject-level predictions. Moving forward, we suggest that methodological caution and new analytical approaches will be needed to confirm (or refute) a systematic character to spontaneous recovery from motor and other poststroke impairments, which can be captured by a mathematical rule either at the population or at the subject level.

中文翻译：

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什么是比例回收规则（和不是）：方法论和统计考虑

2008 年，有人提出，在卒中后的前 3 至 6 个月内，使用 Fugl-Meyer 评估 (FMA) 测量的非严重上肢运动损伤的恢复程度约为初始损伤的 0.7 倍（“比例恢复” ）。与非重度轻瘫患者相比，大约 30% 的初始重度轻瘫患者没有表现出这种恢复（“非恢复者”）。因此，有人提出比例恢复规则 (PRR) 是一种自发机制的表现，存在于所有轻中度麻痹患者中，但仅存在于一些重度麻痹患者中。自从引入 PRR 以来，它随后被应用于其他运动和非运动障碍。对 PRR 的这种更广泛的调查导致了其制定和应用的不一致，使跨研究得出结论变得困难，并引发一些有说服力的批评。在这里，我们对报告比例恢复的不同研究进行了详细比较，并在适当的情况下批评了统计方法。总的来说，我们得出的结论是，现有的总体数据与作为上肢运动恢复的人口水平模型的 PRR 基本一致；最近关于其消亡的报道被夸大了，因为这些报道过度关注个别学科水平预测的不太确定的问题。展望未来，我们建议需要谨慎的方法论和新的分析方法来确认（或反驳）运动和其他中风后损伤自发恢复的系统特征，这可以通过数学规则在人群或受试者中捕获等级。