Hand function improvement in stroke survivors in the chronic stage usually plateaus by 6 months. Brain-computer interface (BCI)-guided robot-assisted training has been shown to be effective for facilitating upper-limb motor function recovery in chronic stroke. However, the underlying neuroplasticity change is not well understood. This study aimed to investigate the whole-brain neuroplasticity changes after 20-session BCI-guided robot hand training, and whether the changes could be maintained at the 6-month follow-up. Therefore, the clinical improvement and the neurological changes before, immediately after, and 6 months after training were explored in 14 chronic stroke subjects. The upper-limb motor function was assessed by Action Research Arm Test (ARAT) and Fugl-Meyer Assessment for Upper-Limb (FMA), and the neurological changes were assessed using resting-state functional magnetic resonance imaging. Repeated-measure ANOVAs indicated that long-term motor improvement was found by both FMA (F[2,26] = 6.367, p = 0.006) and ARAT (F[2,26] = 7.230, p = 0.003). Seed-based functional connectivity analysis exhibited that significantly modulated FC was observed between ipsilesional motor regions (primary motor cortex and supplementary motor area) and contralesional areas (supplementary motor area, premotor cortex, and superior parietal lobule), and the effects were sustained after 6 months. The fALFF analysis showed that local neuronal activities significantly increased in central, frontal and parietal regions, and the effects were also sustained after 6 months. Consistent results in FC and fALFF analyses demonstrated the increase of neural activities in sensorimotor and fronto-parietal regions, which were highly involved in the BCI-guided training. Clinical Trial Registration: This study has been registered at ClinicalTrials.gov with clinical trial registration number NCT02323061.

中文翻译：

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慢性中风脑机接口引导机器人手训练后功能连接和低频波动的调节：一项为期 6 个月的随访研究

慢性期中风幸存者的手功能改善通常在 6 个月后趋于稳定。脑机接口 (BCI) 引导的机器人辅助训练已被证明可有效促进慢性中风患者的上肢运动功能恢复。然而，潜在的神经可塑性变化尚不清楚。本研究旨在调查 20 次 BCI 引导的机器人手训练后全脑神经可塑性的变化，以及这些变化是否能在 6 个月的随访中保持。因此，在 14 名慢性卒中受试者中探索了训练前、训练后立即和训练后 6 个月的临床改善和神经系统变化。上肢运动功能通过动作研究手臂测试 (ARAT) 和 Fugl-Meyer 上肢评估 (FMA) 进行评估，使用静息状态功能磁共振成像评估神经系统变化。重复测量方差分析表明，FMA (F[2,26] = 6.367, p = 0.006) 和 ARAT (F[2,26] = 7.230, p = 0.003) 均发现长期运动改善。基于种子的功能连接分析表明，在同侧运动区（初级运动皮层和辅助运动区）和对侧运动区（补充运动区、前运动皮层和顶上小叶）之间观察到显着调节的 FC，并且这种影响在 6 年后持续个月。fALFF 分析表明，中央、额叶和顶叶区域的局部神经元活动显着增加，并且效果在 6 个月后也持续。FC 和 fALFF 分析的一致结果表明，感觉运动和额顶叶区域的神经活动增加，这些区域高度参与 BCI 引导的训练。临床试验注册：本研究已在 ClinicalTrials.gov 注册，临床试验注册号为 NCT02323061。