Rocca Maria A, Gavazzi Cinzia, Mezzapesa Domenico M, Falini Andrea, Colombo Bruno, Mascalchi Mario, Scotti Giuseppe, Comi Giancarlo, Filippi Massimo
Neuroimaging Research Unit, Scientific Institute and University Ospedale San Raffaele, Via Olgettina 60, 20132 Milan, Italy.
Neuroimage. 2003 Aug;19(4):1770-7. doi: 10.1016/s1053-8119(03)00242-8.
Although several functional magnetic resonance imaging (fMRI) studies have shown adaptive cortical changes in patients with early multiple sclerosis (MS), the presence of brain plasticity and its role in limiting the functional consequences of brain tissue damage in patients with secondary progressive (SP) MS have not been fully investigated yet. In this study, we assessed the movement-associated brain pattern of cortical activations in patients with SPMS and investigated whether the extent of cortical brain activations is correlated with the extent of brain structural changes. From 13 right-handed SPMS patients and 15 sex- and age-matched healthy volunteers, we obtained: (a) brain dual-echo scans; (b) brain mean diffusivity and fractional anisotropy maps of the normal-appearing white (NAWM) and gray matter (NAGM); (c) fMRI during the performance of simple motor tasks [flexion-extension of the last four fingers of the right hand (task 1) and flexion-extension of the right foot (task 2)]. Compared to healthy volunteers, during task 1 performance, SPMS patients showed more significant activations of the ipsilateral inferior frontal gyrus, middle frontal gyrus, bilaterally, and contralateral intraparietal sulcus. During task 2 performance, SPMS patients had more significant activations of the contralateral primary sensorimotor cortex and thalamus and of the ipsilateral upper bank of sylvian fessure. For both tasks, strong correlations (r values ranging from -0.83 to 0.88) were found between relative activations of cortical areas of the motor network and the severity of structural changes of the NAWM and NAGM. This study demonstrates that cortical plasticity does occur in patients with SPMS and that it might have a role in limiting the clinical impact of MS-related damage. It also suggests that, in these patients, functional abilities are sustained by increased recruitment of highly specialized cortical areas.
尽管多项功能磁共振成像（fMRI）研究已显示早期多发性硬化症（MS）患者存在适应性皮质变化，但脑可塑性的存在及其在限制继发进展型（SP）MS患者脑组织损伤功能后果中的作用尚未得到充分研究。在本研究中，我们评估了SPMS患者与运动相关的皮质激活脑模式，并研究了皮质脑激活程度是否与脑结构变化程度相关。我们从13名右利手SPMS患者和15名性别及年龄匹配的健康志愿者身上获取了：（a）脑部双回波扫描；（b）正常外观白质（NAWM）和灰质（NAGM）的脑平均扩散率和分数各向异性图；（c）在执行简单运动任务[右手最后四指的屈伸（任务1）和右脚的屈伸（任务2）]期间的fMRI。与健康志愿者相比，在执行任务1时，SPMS患者同侧额下回、额中回双侧以及对侧顶内沟的激活更为显著。在执行任务2时，SPMS患者对侧初级感觉运动皮层、丘脑以及同侧外侧裂上壁的激活更为显著。对于这两项任务，在运动网络皮质区域的相对激活与NAWM和NAGM结构变化的严重程度之间均发现了强相关性（r值范围为 -0.83至0.88）。本研究表明，SPMS患者确实存在皮质可塑性，并且它可能在限制MS相关损伤的临床影响方面发挥作用。研究还表明，在这些患者中，功能能力是通过增加对高度专业化皮质区域的募集来维持的。
