Previous research has demonstrated hemisphere-specific motor deficits in ipsilesional and contralesional unimanual movements in patients with hemiparetic stroke due to MCA infarct. Due to the importance of bilateral motor actions on activities of daily living, we now examine how bilateral coordination may be differentially affected by right or left hemisphere stroke. To avoid the caveat of simply adding unimanual deficits in assessing bimanual coordination, we designed a unique task that requires spatiotemporal coordination features that do not exist in unimanual movements. Participants with unilateral left (LHD) or right hemisphere damage (RHD) and age-matched controls moved a virtual rectangle (bar) from a midline start position to a midline target. Movement along the long axis of the bar was redundant to the task, such that the bar remained in the center of and parallel to an imaginary line connecting each hand. Thus, to maintain midline position of the bar, movements of one hand closer to or further away from the bar midline required simultaneous, but oppositely directed displacements with the other hand. Our findings indicate that left (LHD), but not right (RHD) hemisphere-damaged patients showed poor interlimb coordination, reflected by significantly lower correlations between displacements of each hand along the bar axis. These left hemisphere-specific deficits were only apparent prior to peak velocity, likely reflecting predictive control of interlimb coordination. In contrast, the RHD group bilateral coordination was not significantly different than that of the control group. We conclude that predictive mechanisms that govern bilateral coordination are dependent on left hemisphere mechanisms. These findings indicate that assessment and training in cooperative bimanual tasks should be considered as part of an intervention framework for post-stroke physical rehabilitation.

先前的研究表明，由于 MCA 梗塞导致的偏瘫卒中患者的同侧和对侧单手运动存在半球特异性运动缺陷。由于双侧运动动作对日常生活活动的重要性，我们现在研究双侧协调性如何受到右半球或左半球中风的不同影响。为了避免在评估双手协调时简单地添加单手缺陷的警告，我们设计了一项独特的任务，该任务需要单手运动中不存在的时空协调特征。患有单侧左半球 (LHD) 或右半球损伤 (RHD) 且年龄匹配的对照的参与者将虚拟矩形（条）从中线起始位置移动到中线目标。沿着杠铃的长轴移动对于这项任务来说是多余的，因此杠铃保持在连接每只手的假想线的中心并平行于一条假想线。因此，为了保持杆的中线位置，一只手靠近或远离杆中线的运动需要另一只手同时进行但方向相反的位移。我们的研究结果表明，左半球（LHD）而非右半球（RHD）受损的患者表现出肢体间协调性较差，这反映在每只手沿杆轴的位移之间的相关性显着较低。这些左半球特异性缺陷仅在达到峰值速度之前才明显，可能反映了肢体间协调的预测控制。相比之下，RHD 组双侧协调性与对照组没有显着差异。我们的结论是，控制双边协调的预测机制依赖于左半球机制。 这些发现表明，合作双手任务的评估和训练应被视为中风后身体康复干预框架的一部分。