Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Beomo-ri, Mulgum-eup, Yangsan, Gyeongsangnam-do 626-770, South Korea.
J Neurol. 2013 Aug;260(8):2094-101. doi: 10.1007/s00415-013-6951-x. Epub 2013 May 14.
It is a matter of debate whether increased brain iron levels are the cause or only the consequence of neurodegenerative process in degenerative parkinsonism. The aim of this study is to characterize disease-related changes in volumes and iron-related R2 values of basal ganglia and thalamus. 13 patients with progressive supranuclear palsy (PSP), 15 with a parkinsonian variant of multiple system atrophy (MSA-p), 29 with Parkinson's disease (PD), and 21 age-matched controls underwent 3-Tesla MRI. The R2 values and volumes were calculated for the selected subcortical structures (caudate nucleus, putamen, globus pallidus, and thalamus) using an automated region-based analysis. Voxel-based analysis was also performed to visualize a topographical correlation of R2 value and volume. The PSP group had significantly higher R2 values in globus pallidus and caudate nucleus (p < 0.05), whereas the MSA-p group had higher R2 values in putamen (p < 0.001) than PD and controls. The globus pallidus in PSP and the putamen in MSA-p were the most significant areas of atrophy to differentiate PSP, MSA-p and PD (AUC = 0.856, 0.832, respectively, p < 0.001). The R2 values in both structures increased in parallel with the extent of atrophy. They were negatively correlated with volumes in putamen (r = -0.777, p < 0.001) and globus pallidus (r = -0.409, p = 0.025) of MSA-p, and globus pallidus (r = -0.4, p = 0.043) of PSP. Voxel-based analysis identified higher R2 values in more severely atrophic sub-regions in these structures. We observed topographical differences of iron deposition as well as atrophy between MSA-p and PSP. Increased iron levels were related to the structural atrophy in basal ganglia. Our results imply that iron accumulation is likely an epiphenomenon of the degenerative process.
脑铁含量的增加是神经退行性变过程中的原因还是结果尚存在争议。本研究旨在描述进行性核上性麻痹（PSP）、帕金森病（PD）和多系统萎缩（MSA）患者基底节和丘脑体积和铁相关 R2 值的变化。13 例进行性核上性麻痹（PSP）患者、15 例帕金森病变异型多系统萎缩（MSA-p）患者、29 例帕金森病（PD）患者和 21 名年龄匹配的对照组接受了 3T MRI 检查。使用基于自动区域分析的方法计算选定的皮质下结构（尾状核、壳核、苍白球和丘脑）的 R2 值和体积。还进行了体素分析，以可视化 R2 值和体积的拓扑相关性。PSP 组苍白球和尾状核的 R2 值明显较高（p<0.05），而 MSA-p 组壳核的 R2 值明显较高（p<0.001），PD 和对照组。PSP 的苍白球和 MSA-p 的壳核是区分 PSP、MSA-p 和 PD 的最显著萎缩区域（AUC=0.856、0.832，分别，p<0.001）。这两种结构的 R2 值与萎缩程度呈平行增加。它们与 MSA-p 壳核（r=-0.777，p<0.001）和苍白球（r=-0.409，p=0.025）以及 PSP 苍白球（r=-0.4，p=0.043）的体积呈负相关。体素分析确定了这些结构中萎缩更严重的亚区的 R2 值更高。我们观察到 MSA-p 和 PSP 之间铁沉积和萎缩的拓扑差异。铁含量的增加与基底节的结构萎缩有关。我们的研究结果表明，铁积累可能是退行性过程的继发现象。
