Sporn Sebastian, Bonyadi E, Fathana R, Tedesco Triccas L, Coll M, Bestmann S, Ward N S
Department of Clinical and Movement Neuroscience, Queens Square Institute of Neurology, UCL, London, UK.
Speech, Hearing and Phonetic Science, Psychology and Language Science, UCL, London, UK.
J Neuroeng Rehabil. 2025 Jun 18;22(1):135. doi: 10.1186/s12984-025-01661-5.
A proportion of stroke survivors use their paretic arm less than might be expected based on their level of impairment. The resulting underuse of the paretic arm has a negative impact on participation in neurorehabilitation and functional independence. However, non-use remains poorly understood. One possibility is that prioritising the non-paretic arm reflects a habit, despite residual functional capacity in the paretic arm.
30 chronic stroke survivors (Mean Fugl Meyer Upper Limb Score: 28.9 ± 11.3) participated in a simplified version of the forced response paradigm, which reliably identifies the presence of a habit. Participants were asked to choose which arm to use to maximise points scored during a reaching task. During half of the trials, the presumed habit of using the non-paretic arm yielded more points, whereas in the other half using the non-paretic arm incurred a loss of points. Participants completed two versions of this task, once with unlimited response time available and once without.
Participants scored fewer points in the limited response condition compared to the unlimited response conditions. This difference was driven by a selective increase in the use of the non-paretic arm in trials where the paretic arm yielded more points. The results were not mediated by former hand dominance.
Our results demonstrate that not using the non-paretic arm may reflect a habit response that is more readily triggered in demanding (e.g. time-limited) situations. This may explain why successful neurorehabilitation does not always result in a more functionally useful arm. Our results pave the way for targeted interventions such as habit breaking techniques to be included in clinical practise.
一部分中风幸存者对其患侧手臂的使用少于基于其损伤程度所预期的使用量。由此导致的患侧手臂使用不足对神经康复参与度和功能独立性产生负面影响。然而，对不使用患侧手臂的情况仍了解不足。一种可能性是，优先使用非患侧手臂反映了一种习惯，尽管患侧手臂仍有残余功能。
30名慢性中风幸存者（平均Fugl Meyer上肢评分：28.9±11.3）参与了强制反应范式的简化版本，该版本能可靠地识别习惯的存在。参与者被要求选择使用哪只手臂以在伸手够物任务中获得最高分。在一半的试验中，使用非患侧手臂的假定习惯能获得更多分数，而在另一半试验中，使用非患侧手臂会导致分数损失。参与者完成了该任务的两个版本，一次是有无限反应时间，一次是没有无限反应时间。
与无限反应条件相比，参与者在有限反应条件下得分更低。这种差异是由在患侧手臂能获得更多分数的试验中，非患侧手臂使用的选择性增加所驱动的。结果不受先前用手习惯的影响。
我们的结果表明，不使用患侧手臂可能反映了一种习惯反应，这种反应在要求较高（如时间有限）的情况下更容易被触发。这可能解释了为什么成功的神经康复并不总是能带来功能上更有用的手臂。我们的结果为在临床实践中纳入针对性干预措施（如习惯打破技术）铺平了道路。
