Pantano Patrizia, Mainero Caterina, Caramia Francesca
Department of Neurological Sciences, University La Sapienza, Viale dell'Università 30, 00185 Rome, Italy.
J Neuroimaging. 2006 Apr;16(2):104-14. doi: 10.1111/j.1552-6569.2006.00029.x.
In patients with multiple sclerosis (MS), the severity of clinical signs is not closely related to indices of structural brain damage provided by conventional magnetic resonance MR. Accordingly, patients with MS may show symptom recovery while progressively accumulating tissue damage. Changes in functional organization of the cerebral cortex have been reported in functional magnetic resonance (fMRI) studies that have compared the activation patterns during motor, visual, and cognitive tasks of patients with MS with those of healthy controls. fMRI studies on MS have provided the results that are difficult to compare and may be discrepant because of differences in the criteria used for patient selection, the activation paradigm, the experimental design, and the MR acquisition parameters. Nevertheless, they do provide a new, interesting tool that sheds light on how the brain changes its functional organization in response to MS. In patients with MS, functional brain reorganization mainly consists of an increase in the extent of activation of the brain areas used by healthy subjects, as well as the recruitment of additional brain areas. These findings have been interpreted as adaptive or compensatory mechanisms that allow normal performance despite neural damage or loss. However, brain functional activity may also change in response to clinical disability, though the precise role of brain functional changes in MS has yet to fully understand. Longitudinal studies designed to explore the effects of both rehabilitation and pharmacological agents on brain plasticity might shed light on this issue.
在多发性硬化症（MS）患者中，临床体征的严重程度与传统磁共振成像（MR）所提供的脑结构损伤指标并无密切关联。因此，MS患者可能在逐渐累积组织损伤的同时出现症状缓解。在功能磁共振成像（fMRI）研究中，已报告了大脑皮层功能组织的变化，这些研究比较了MS患者与健康对照者在运动、视觉和认知任务期间的激活模式。针对MS的fMRI研究所得结果难以比较，且可能存在差异，原因在于患者选择标准、激活范式、实验设计以及MR采集参数的不同。尽管如此，它们确实提供了一种全新且有趣的工具，有助于揭示大脑如何因应MS而改变其功能组织。在MS患者中，大脑功能重组主要包括健康受试者所使用脑区激活范围的增加，以及额外脑区的募集。这些发现被解释为适应性或代偿性机制，尽管存在神经损伤或丧失，但仍能实现正常表现。然而，大脑功能活动也可能因临床残疾而发生变化，尽管MS中大脑功能变化的确切作用尚未完全明了。旨在探究康复和药物制剂对脑可塑性影响的纵向研究可能会阐明这一问题。
