Bonzano Laura, Pardini Matteo, Mancardi Gian Luigi, Pizzorno Matteo, Roccatagliata Luca
Department of Neurosciences, Ophthalmology and Genetics (DINOG), Via De Toni, 5-16132, Genoa, Italy.
Neuroimage. 2009 Jan 1;44(1):9-15. doi: 10.1016/j.neuroimage.2008.08.015. Epub 2008 Aug 26.
To assess the influence of white matter pathology on cortical reorganization, we probed the fronto-parietal attention network in Multiple Sclerosis (MS) patients by combining the Paced Visual Serial Addition Test (PVSAT) with fMRI-guided fiber tractography (FT). During the PVSAT, the control subjects activated the left inferior parietal lobule, superior temporal gyrus, precuneus, precentral gyrus, and medial and middle frontal gyri; while the precuneus and the inferior parietal lobule gyrus bilaterally, the left precentral and angular gyri and the right superior parietal lobule were activated in the MS group. At fMRI-guided FT, the superior longitudinal fasciculus (SLF) was the main white matter tract connecting areas active during the PVSAT. We then identified two subgroups of MS patients according to the SLF mean Fractional Anisotropy, used as indicator of integrity. The activations of the MS patients with a less damaged tract were in the left hemisphere, similarly to controls; while the patients with a more damaged SLF showed bilateral cortical activations. The MS subgroups, however, did not differ in PVSAT performance. This approach could be useful to investigate the relationship between brain structural and functional plastic changes and to identify different MRI endophenotypes related to the same level of cognitive impairment.
为评估白质病变对皮质重组的影响，我们通过将视觉序列加法测试（PVSAT）与功能磁共振成像引导的纤维束成像（FT）相结合，对多发性硬化症（MS）患者的额顶叶注意力网络进行了探测。在PVSAT期间，对照组激活了左侧顶下小叶、颞上回、楔前叶、中央前回以及额内侧回和额中回；而在MS组中，双侧楔前叶和顶下小叶回、左侧中央前回和角回以及右侧顶上小叶被激活。在功能磁共振成像引导的FT中，上纵束（SLF）是连接PVSAT期间活跃区域的主要白质束。然后，我们根据用作完整性指标的SLF平均分数各向异性，将MS患者分为两个亚组。白质束受损较轻的MS患者的激活位于左侧半球，与对照组相似；而SLF受损较重的患者则表现出双侧皮质激活。然而，MS亚组在PVSAT表现上并无差异。这种方法可能有助于研究脑结构和功能可塑性变化之间的关系，并识别与相同认知障碍水平相关的不同MRI内表型。
