Division of Biokinesiology and Physical Therapy at the School of Dentistry, and Department of Computer Science, University of Southern California, Los Angeles, CA 90089, USA.
Phys Ther. 2009 Dec;89(12):1327-36. doi: 10.2522/ptj.20080402. Epub 2009 Oct 1.
Although spontaneous use of the more-affected arm and hand after stroke is an important determinant of participation and quality of life, a number of patients exhibit decreases in use following rehabilitative therapy. A previous neurocomputational model predicted that if the dose of therapy is sufficient to bring performance above a certain threshold, training can be stopped.
The aim of this study was to test the hypothesis that there exists a threshold for function of the paretic arm and hand after therapy. If function is above this threshold, spontaneous use will increase in the months following therapy. In contrast, if function is below this threshold, spontaneous use will decrease.
New computer simulations are presented showing that changes in arm use following therapy depend on a performance threshold. This prediction was tested by reanalyzing the data from the Extremity Constraint-Induced Therapy Evaluation (EXCITE) trial, a phase III randomized controlled trial in which participants received constraint-induced movement therapy for 2 weeks and were tested both 1 week and 1 year after therapy.
The results demonstrate that arm and hand function measured immediately after therapy predicts, on average, the long-term change of arm use. Above a functional threshold, use improves. Below this threshold, use decreases.
The reanalysis of the EXCITE trial data provides a "group" threshold above which a majority of patients, but not all, improve spontaneously. A goal of future research is to provide the means to assess when patients reach their individual threshold.
Understanding of the causal and nonlinear relationship between limb function and daily use is important for the future development of cost-effective interventions and prevention of "rehabilitation in vain."
尽管中风后自发性地使用患肢和患手是参与和生活质量的重要决定因素，但许多患者在康复治疗后会减少使用。先前的神经计算模型预测，如果治疗剂量足以使表现超过一定的阈值，就可以停止训练。
本研究的目的是检验这样一种假设，即在治疗后，患侧手臂和手的功能存在一个阈值。如果功能高于这个阈值，那么在治疗后的几个月里，自发性使用会增加。相反，如果功能低于这个阈值，自发性使用将会减少。
新的计算机模拟表明，治疗后手臂使用的变化取决于功能阈值。通过重新分析极端约束诱导治疗评估（EXCITE）试验的数据来检验这一预测，这是一项 III 期随机对照试验，参与者接受了为期 2 周的强制性运动疗法治疗，并在治疗后 1 周和 1 年进行了测试。
结果表明，治疗后立即测量的手臂和手部功能平均预测了手臂使用的长期变化。在功能阈值以上，使用会得到改善。低于这个阈值，使用会减少。
对 EXCITE 试验数据的重新分析提供了一个“群体”阈值，超过这个阈值，大多数患者，但不是所有患者，都会自发地改善。未来研究的目标是提供评估患者何时达到其个体阈值的方法。
理解肢体功能和日常使用之间的因果和非线性关系对于未来开发具有成本效益的干预措施和防止“无效康复”是重要的。
