Medical Faculty, University of Cologne, and Department of Neurology, University Hospital Cologne, Cologne, Germany.
Institute of Neuroscience and Medicine, Cognitive Neuroscience (INM-3), Research Centre Juelich, Juelich, Germany.
Ann Neurol. 2023 Oct;94(4):785-797. doi: 10.1002/ana.26737. Epub 2023 Jul 25.
Although ample evidence highlights that the ipsilesional corticospinal tract (CST) plays a crucial role in motor recovery after stroke, studies on cortico-cortical motor connections remain scarce and provide inconclusive results. Given their unique potential to serve as structural reserve enabling motor network reorganization, the question arises whether cortico-cortical connections may facilitate motor control depending on CST damage.
Diffusion spectrum imaging (DSI) and a novel compartment-wise analysis approach were used to quantify structural connectivity between bilateral cortical core motor regions in chronic stroke patients. Basal and complex motor control were differentially assessed.
Both basal and complex motor performance were correlated with structural connectivity between bilateral premotor areas and ipsilesional primary motor cortex (M1) as well as interhemispheric M1 to M1 connectivity. Whereas complex motor skills depended on CST integrity, a strong association between M1 to M1 connectivity and basal motor control was observed independent of CST integrity especially in patients who underwent substantial motor recovery. Harnessing the informational wealth of cortico-cortical connectivity facilitated the explanation of both basal and complex motor control.
We demonstrate for the first time that distinct aspects of cortical structural reserve enable basal and complex motor control after stroke. In particular, recovery of basal motor control may be supported via an alternative route through contralesional M1 and non-crossing fibers of the contralesional CST. Our findings help to explain previous conflicting interpretations regarding the functional role of the contralesional M1 and highlight the potential of cortico-cortical structural connectivity as a future biomarker for motor recovery post-stroke. ANN NEUROL 2023;94:785-797.
尽管大量证据表明，病变对侧皮质脊髓束（CST）在中风后运动功能恢复中起着至关重要的作用，但皮质-皮质运动连接的研究仍然很少，且结果尚无定论。鉴于皮质连接具有作为结构储备的独特潜力，能够促进运动网络重组，那么问题就出现了：皮质连接是否可以根据 CST 损伤来促进运动控制。
采用弥散张量成像（DSI）和一种新的分区分析方法，定量分析慢性中风患者双侧皮质核心运动区之间的结构连接。分别评估了基础运动和复杂运动控制能力。
基础运动和复杂运动表现均与双侧运动前区与病变侧初级运动皮质（M1）之间以及双侧 M1 之间的结构连接相关。复杂运动技能依赖于 CST 的完整性，而 M1 与 M1 之间的连接与基础运动控制之间存在很强的关联，且与 CST 的完整性无关，尤其是在那些经历了大量运动恢复的患者中。利用皮质连接的信息丰富性，可以很好地解释基础和复杂运动控制。
我们首次证明了皮质结构储备的不同方面可以在中风后实现基础和复杂的运动控制。特别是，通过对侧 M1 和对侧 CST 的非交叉纤维，可通过替代途径来恢复基础运动控制。我们的研究结果有助于解释先前关于对侧 M1 的功能作用的相互矛盾的解释，并强调了皮质连接结构连接作为中风后运动恢复的未来生物标志物的潜力。
