Background. Recovery of upper limb function post-stroke can be partly predicted by initial motor function, but the mechanisms underpinning these improvements have yet to be determined. Here, we sought to identify neural correlates of post-stroke recovery using longitudinal magnetoencephalography (MEG) assessments in subacute stroke survivors. Methods. First-ever, subcortical ischemic stroke survivors with unilateral mild to moderate hand paresis were evaluated at 3, 5, and 12 weeks after stroke using a finger-lifting task in the MEG. Cortical activity patterns in the β-band (16-30 Hz) were compared with matched healthy controls. Results. All stroke survivors (n=22; 17 males) had improvements in action research arm test (ARAT) and Fugl-Meyer upper extremity (FM-UE) scores between 3 and 12 weeks. At 3 weeks post-stroke the peak amplitudes of the movement-related ipsilesional β-band event-related desynchronization (β-ERD) and synchronization (β-ERS) in primary motor cortex (M1) were significantly lower than the healthy controls (p<0.001) and were correlated with both the FM-UE and ARAT scores (r=0.51-0.69, p<0.017). The decreased β-ERS peak amplitudes were observed both in paretic and non-paretic hand movement particularly at 3 weeks post-stroke, suggesting a generalized disinhibition status. The peak amplitudes of ipsilesional β-ERS at week 3 post-stroke correlated with the FM-UE score at 12 weeks (r=0.54, p=0.03) but no longer significant when controlling for the FM-UE score at 3 weeks post-stroke.Conclusions. Although early β-band activity does not independently predict outcome at 3 months after stroke, it mirrors functional changes, giving a potential insight into the mechanisms underpinning recovery of motor function in subacute stroke.

中文翻译：

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β-振荡反映亚急性中风麻痹性上肢的恢复

背景。中风后上肢功能的恢复可以部分通过初始运动功能来预测，但支持这些改善的机制尚未确定。在这里，我们试图在亚急性中风幸存者中使用纵向脑磁图 (MEG) 评估来确定中风后恢复的神经相关性。方法。首次在脑卒中后 3、5 和 12 周使用 MEG 中的手指提升任务对单侧轻度至中度手部麻痹的皮层下缺血性卒中幸存者进行评估。将 β 波段 (16-30 Hz) 的皮质活动模式与匹配的健康对照进行比较。结果。所有中风幸存者（n = 22；17 名男性）在 3 至 12 周之间在行动研究手臂测试 (ARAT) 和 Fugl-Meyer 上肢 (FM-UE) 评分方面都有所改善。在中风后 3 周，初级运动皮层 (M1) 中运动相关的同侧 β 带事件相关去同步化 (β-ERD) 和同步化 (β-ERS) 的峰值幅度显着低于健康对照 (p <0.001) 并且与 FM-UE 和 ARAT 分数相关 (r=0.51-0.69, p<0.017)。在麻痹和非麻痹手部运动中均观察到 β-ERS 峰值幅度降低，特别是在中风后 3 周，表明存在普遍的去抑制状态。卒中后第 3 周的同侧 β-ERS 峰值幅度与 12 周时的 FM-UE 评分相关（r=0.54，p=0.03），但在控制后 3 周的 FM-UE 评分时不再显着中风。结论。尽管早期 β 波段活动不能独立预测卒中后 3 个月的结果，