Mainero Caterina, Pantano Patrizia, Caramia Francesca, Pozzilli Carlo
Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, 02129, USA.
J Neurol Sci. 2006 Jun 15;245(1-2):93-8. doi: 10.1016/j.jns.2005.08.024. Epub 2006 Apr 19.
Deficits in memory and attention frequently occur during the course of multiple sclerosis (MS). In patients with MS the severity of cognitive manifestations is not closely related to indices of structural brain damage on both conventional and non conventional magnetic resonance imaging (MRI). It is conceivable that the ability of the brain to compensate for tissue impairment or loss may contribute to the maintenance of normal performance despite scattered brain lesions. Accordingly, using functional MRI (fMRI), patients with multiple sclerosis showed a greater extent of brain activation during motors tasks than controls. Changes in functional organization of the cerebral cortex have also been reported by fMRI studies comparing the activation patterns during cognitive tasks in patients with MS and in healthy subjects. Differences in patients' selection, activation paradigm, experimental design and MR acquisition parameters make, however, the results obtained from fMRI studies difficult to be compared and may explain, at least partially, some discrepant findings. Nevertheless, fMRI studies provide a new interesting way of understanding how the brain can change its functional organization in response to MS pathology, and might be useful in the study of the effects of either rehabilitation or pharmacological agents on brain plasticity.
记忆和注意力缺陷在多发性硬化症（MS）病程中经常出现。在MS患者中，认知表现的严重程度与传统和非传统磁共振成像（MRI）上脑结构损伤指标并无密切关联。可以想象，尽管存在散在的脑损伤，但大脑补偿组织损伤或损失的能力可能有助于维持正常功能。因此，通过功能磁共振成像（fMRI）发现，与对照组相比，多发性硬化症患者在运动任务期间大脑激活程度更高。fMRI研究比较了MS患者和健康受试者在认知任务期间的激活模式，也报告了大脑皮层功能组织的变化。然而，患者选择、激活范式、实验设计和磁共振采集参数的差异使得fMRI研究结果难以比较，这可能至少部分解释了一些相互矛盾的发现。尽管如此，fMRI研究为理解大脑如何响应MS病理改变其功能组织提供了一种新的有趣方式，并且可能有助于研究康复或药物对脑可塑性的影响。
