Schulz Robert, Park Eunhee, Lee Jungsoo, Chang Won Hyuk, Lee Ahee, Kim Yun-Hee, Hummel Friedhelm C
Dept. of Neurology, University Medical Center Hamburg-Eppendorf, Germany.
Dept. of Physical and Rehabilitation Medicine, Center for Prevention and Rehabilitation, Heart Vascular and Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
Neuroimage Clin. 2017 Apr 19;15:118-124. doi: 10.1016/j.nicl.2017.04.016. eCollection 2017.
Brain imaging has shown that not only the cortico-spinal tract (CST), but also alternate corticofugal motor fibers (aMF), such as the cortico-rubro-spinal and cortico-reticulo-spinal tract, influence residual motor output after stroke. So far, studies mainly have investigated each tract separately. A combined analysis of CST and aMF with assessment of their interactive role, i.e., that structural integrity of one tract influences the functional role of the structural integrity of the other, is pending.
39 late subacute stroke patients (aged 59.4 ± 12.0 years, 100 ± 11 days after stroke) were included. Probabilistic tractography was used to reconstruct CST and aMF. Fractional anisotropy (FA) was calculated as a measure of microstructural integrity. Multiple-linear-regression analysis was used to associate tract-related FA with residual motor output and to determine interactions between CST and aMF.
Both CST (coefficient = 3.93, < 0.0001) and aMF (coefficient = - 4.43, = 0.003) of the affected hemisphere significantly contributed to residual motor output. An interaction of their impacts with a consecutive influence on motor output was not detected ( = 0.882). Thus, these data suggest that aMF and CST explain residual motor output in stroke patients in a synergistic, but mainly independent manner.
The structural states of the CST and also - to a smaller degree - of the aMF correlate with residual motor output in late subacute stroke patients. Based on this statistical modeling with all inherent limitations, the novel finding of an absence of a significant interaction between both tracts in regard of their functional role, suggests that both corticofugal pathways act synergistically but largely independently. These findings add to the understanding of the functional role of different corticofugal motor fibers and their interactions for motor output after stroke.
脑成像显示，不仅皮质脊髓束（CST），而且其他皮质传出运动纤维（aMF），如皮质红核脊髓束和皮质网状脊髓束，都会影响中风后的残余运动输出。到目前为止，研究主要是分别对每条束进行调查。对CST和aMF进行联合分析，并评估它们的交互作用，即一条束的结构完整性会影响另一条束结构完整性的功能作用，这一工作尚待开展。
纳入39例亚急性后期中风患者（年龄59.4±12.0岁，中风后100±11天）。采用概率性纤维束成像重建CST和aMF。计算分数各向异性（FA）作为微观结构完整性的指标。采用多元线性回归分析将与纤维束相关的FA与残余运动输出相关联，并确定CST和aMF之间的相互作用。
患侧半球的CST（系数=3.93，<0.0001）和aMF（系数=-4.43，=0.003）均对残余运动输出有显著贡献。未检测到它们的影响之间存在对运动输出的连续影响的相互作用（=0.882）。因此，这些数据表明，aMF和CST以协同但主要是独立的方式解释中风患者的残余运动输出。
CST的结构状态以及在较小程度上aMF的结构状态与亚急性后期中风患者的残余运动输出相关。基于这种存在所有固有局限性的统计模型，关于两条束在功能作用方面不存在显著相互作用这一新发现表明，两条皮质传出通路协同作用但在很大程度上相互独立。这些发现有助于加深对不同皮质传出运动纤维的功能作用及其在中风后运动输出方面相互作用的理解。
