Rocca Maria A, Pagani Elisabetta, Ghezzi Angelo, Falini Andrea, Zaffaroni Mauro, Colombo Bruno, Scotti Giuseppe, Comi Giancarlo, Filippi Massimo
Neuroimaging Research Unit, Department of Neuroscience, Scientific Institute, Milan, Italy.
Neuroimage. 2003 Jul;19(3):826-36. doi: 10.1016/s1053-8119(03)00053-3.
Recent functional magnetic resonance imaging (fMRI) work has suggested that cortical reorganisation might have an adaptive role in limiting the clinical impact of multiple sclerosis (MS) structural damage. In this study, we investigated whether, in patients with MS, the presence and extent of structural damage of the normal-appearing brain tissue are associated with the extent of the movement-associated pattern of cortical activations. Using fMRI and a general search method, we assessed the patterns of brain activations associated with simple motor tasks in 12 right-handed patients with clinically definite MS and nonspecific T2-weighted abnormalities on conventional MRI scans of the brain and compared them with those from 12 sex- and age-matched right- handed healthy controls. Also investigated were the extent to which the fMRI changes correlated with normal-appearing white matter and grey matter (GM) pathology, measured using diffusion tensor MRI. When performing the simple motor task with the dominant hand, MS patients had more significant activations of the ipsilateral supplementary motor area (SMA), the ipsilateral superior frontal sulcus, the contralateral superior temporal gyrus, and the thalamus than controls. On the contrary, healthy subjects showed more significant activations of the medial part of the contralateral parieto-occipital fissure and the ipsilateral primary sensorimotor cortex (SMC) than patients with MS. In patients with MS, the relative activation of the ipsilateral SMA was correlated with the peak height (r = -0.88, P < 0.001) and position (r = 0.87, P < 0.001) of the GM mean diffusivity histogram. This study shows that cortical reorganisation occurs over a rather distributed sensorimotor network even in patients with MS and nonspecific abnormalities on conventional brain MRI scans. This suggests that, in patients with MS, an increased recruitment of movement-associated cortical network can be elicited by the presence of normal-appearing tissue pathology, which is independent of macroscopic T2-weighted abnormalities.
近期的功能磁共振成像（fMRI）研究表明，皮质重组可能在限制多发性硬化症（MS）结构损伤的临床影响方面具有适应性作用。在本研究中，我们调查了MS患者中，外观正常的脑组织的结构损伤的存在和程度是否与皮质激活的运动相关模式的程度相关。使用fMRI和一种通用搜索方法，我们评估了12名临床确诊为MS且脑部传统MRI扫描显示非特异性T2加权异常的右利手患者在简单运动任务时的脑激活模式，并将其与12名年龄和性别匹配的右利手健康对照者的脑激活模式进行比较。我们还研究了fMRI变化与使用扩散张量MRI测量的外观正常的白质和灰质（GM）病理学的相关程度。在用优势手执行简单运动任务时，MS患者同侧辅助运动区（SMA）、同侧额上沟、对侧颞上回和丘脑的激活比对照组更显著。相反，健康受试者在对侧顶枕裂内侧部分和同侧初级感觉运动皮层（SMC）的激活比MS患者更显著。在MS患者中，同侧SMA的相对激活与GM平均扩散率直方图的峰值高度（r = -0.88，P < 0.001）和位置（r = 0.87，P < 0.001）相关。这项研究表明，即使在脑部传统MRI扫描显示非特异性异常的MS患者中也会在相当广泛的感觉运动网络上发生皮质重组。这表明，在MS患者中，外观正常的组织病理学的存在可引发与运动相关的皮质网络的更多募集，这与宏观T2加权异常无关。
