Rocca Maria A, Absinta Martina, Valsasina Paola, Ciccarelli Olga, Marino Silvia, Rovira Alex, Gass Achim, Wegner Christiane, Enzinger Christian, Korteweg Tjimen, Sormani Maria Pia, Mancini Laura, Thompson Alan J, De Stefano Nicola, Montalban Xavier, Hirsch Jochen, Kappos Ludwig, Ropele Stephan, Palace Jacqueline, Barkhof Frederik, Matthews Paul M, Filippi Massimo
Department of Neurology, Scientific Institute and University, Ospedale San Raffaele, Milan, Italy.
Hum Brain Mapp. 2009 Aug;30(8):2412-25. doi: 10.1002/hbm.20679.
In this multicenter study, we used dynamic causal modeling to characterize the abnormalities of effective connectivity of the sensorimotor network in 61 patients with multiple sclerosis (MS) compared with 74 age-matched healthy subjects. We also investigated the correlation of such abnormalities with findings derived from structural MRI. In a subgroup of subjects, diffusion tensor (DT) MRI metrics of the corpus callosum and the left corticospinal tract (CST) were also assessed. MS patients showed increased effective connectivity relative to controls between: (a) the left primary SMC and the left dorsal premotor cortex (PMd), (b) the left PMd and the supplementary motor areas (SMA), (c) the left secondary sensorimotor cortex (SII) and the SMA, (d) the right SII and the SMA, (e) the left SII and the right SII, and (f) the right SMC and the SMA. MS patients had relatively reduced effective connectivity between the left SMC and the right cerebellum. No interaction was found between disease group and center. Coefficients of altered connectivity were weakly correlated with brain T2 LV, but moderately correlated with DT MRI-measured damage of the left CST. In conclusion, large multicenter fMRI studies of effective connectivity changes in diseased people are feasible and can facilitate studies with sample size large enough for robust outcomes. Increased effective connectivity in the patients for the simple motor task suggests local network modulation contributing to enhanced long-distance effective connectivity in MS patients. This extends and generalizes previous evidence that enhancement of effective connectivity may provide an important compensatory mechanism in MS.
在这项多中心研究中，我们使用动态因果模型来描述61例多发性硬化症（MS）患者与74例年龄匹配的健康受试者相比，感觉运动网络有效连接性的异常情况。我们还研究了这些异常与结构MRI结果之间的相关性。在一个亚组受试者中，还评估了胼胝体和左侧皮质脊髓束（CST）的扩散张量（DT）MRI指标。与对照组相比，MS患者在以下区域之间的有效连接性增加：（a）左侧初级感觉运动皮层（SMC）和左侧背侧运动前皮层（PMd），（b）左侧PMd和辅助运动区（SMA），（c）左侧次级感觉运动皮层（SII）和SMA，（d）右侧SII和SMA，（e）左侧SII和右侧SII，以及（f）右侧SMC和SMA。MS患者左侧SMC和右侧小脑之间的有效连接性相对降低。未发现疾病组与研究中心之间存在交互作用。连接性改变的系数与脑T2病变体积呈弱相关，但与DT MRI测量的左侧CST损伤呈中度相关。总之，对患病个体有效连接性变化进行大型多中心功能磁共振成像研究是可行的，并且可以促进样本量足够大以获得可靠结果的研究。患者在简单运动任务中有效连接性增加表明局部网络调节有助于增强MS患者的长距离有效连接性。这扩展并概括了先前的证据，即有效连接性增强可能在MS中提供重要的代偿机制。
