Faculty of Medicine and University Hospital Cologne, Department of Neurology, University of Cologne, 50931 Cologne, Germany.
Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, 52428 Jülich, Germany.
Cereb Cortex. 2021 Jan 5;31(2):993-1007. doi: 10.1093/cercor/bhaa270.
Hemiparesis after stroke is associated with increased neural activity not only in the lesioned but also in the contralesional hemisphere. While most studies have focused on the role of contralesional primary motor cortex (M1) activity for motor performance, data on other areas within the unaffected hemisphere are scarce, especially early after stroke. We here combined functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) to elucidate the contribution of contralesional M1, dorsal premotor cortex (dPMC), and anterior intraparietal sulcus (aIPS) for the stroke-affected hand within the first 10 days after stroke. We used "online" TMS to interfere with neural activity at subject-specific fMRI coordinates while recording 3D movement kinematics. Interfering with aIPS activity improved tapping performance in patients, but not healthy controls, suggesting a maladaptive role of this region early poststroke. Analyzing effective connectivity parameters using a Lasso prediction model revealed that behavioral TMS effects were predicted by the coupling of the stimulated aIPS with dPMC and ipsilesional M1. In conclusion, we found a strong link between patterns of frontoparietal connectivity and TMS effects, indicating a detrimental influence of the contralesional aIPS on motor performance early after stroke.
脑卒中后偏瘫与损伤对侧半球以及健侧半球的神经活动增加有关。虽然大多数研究都集中在对侧初级运动皮层（M1）活动对运动表现的作用，但关于健侧半球其他区域的数据却很少，尤其是在脑卒中后早期。在这里，我们结合功能磁共振成像（fMRI）和经颅磁刺激（TMS），在脑卒中后 10 天内阐明了对侧 M1、背侧运动前皮质（dPMC）和前顶内沟（aIPS）对患侧手的贡献。我们使用“在线”TMS 在记录 3D 运动运动学的同时，干扰特定于受试者的 fMRI 坐标处的神经活动。干扰 aIPS 活动可改善患者的叩击表现，但不能改善健康对照组的表现，提示该区域在脑卒中后早期具有适应不良的作用。使用套索预测模型分析有效连接参数表明，行为 TMS 效应可通过刺激 aIPS 与 dPMC 和同侧 M1 的耦合来预测。总之，我们发现额叶顶叶连接模式与 TMS 效应之间存在很强的联系，表明脑卒中后早期对侧 aIPS 对运动表现有不利影响。
