A study of the mechanisms of normal-appearing white matter damage in multiple sclerosis using diffusion tensor imaging - Evidence of Wallerian degeneration
A study of the mechanisms of normal-appearing white matter damage in multiple sclerosis using diffusion tensor imaging - Evidence of Wallerian degeneration
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DOI：
10.1007/s00415-003-0992-5
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发表时间：
2003-03-01
影响因子：
6
通讯作者：
Thompson, AJ
中科院分区：
文献类型：
--
作者：
Ciccarelli, O;Werring, DJ;Thompson, AJ
扩散张量成像（DTI）可研究体内脑组织的微观结构。在多发性硬化症 (MS) 中，穿过病灶的轴突的华勒变性是正常白质损伤的潜在机制。该假设的体内证据有限。本研究调查了正常胼胝体 (CC) 中的 DTI 衍生指数与相连大脑区域的病变负荷 (LL) 之间的关系。对 39 名 MS 患者和 21 名年龄匹配的对照者进行了 DTI。评估了 CC 的膝部、体部和压部的分数各向异性 (FA) 和平均扩散率 (MD)。与对照组相比，患者在 CC 中表现出较低的 FA 和较高的 MD，并且两者均与总 LL 相关（r = -0.56 和 r = 0.54，p < 0.0001）。各个脑叶的 LL 与相应胼胝体区域的 FA 和 MD 相关，其中身体与额叶和顶叶 LL 的相关性最强 (p < 0.0001)。 CC 中的 DTI 指数与相连脑区病变范围之间的强相关性支持这样的假设：被远程但相连的局灶性病变横断的轴突的沃勒变性是 MS 损伤的重要致病机制。
Diffusion tensor imaging (DTI) investigates brain tissue microstructure in vivo. In multiple sclerosis (MS) Wallerian degeneration of axons traversing focal lesions is a potential mechanism of damage in normal-appearing white matter. In vivo evidence for this hypothesis is limited. The present study investigated the relationship between DTI-derived indices in the normal-appearing corpus callosum (CC) and the lesion loads (LLs) in connected cerebral regions. DTI was performed in 39 MS patients and in 21 age-matched controls. Fractional anisotropy (FA) and mean diffusivity (MD) were estimated in the genu, body and splenium of CC. Patients showed lower FA and higher MD in the CC than controls and both correlated with the total LL (r = -0.56 and r = 0.54, p < 0.0001). The LL of individual cerebral lobes correlated with both FA and MD in the corresponding callosal regions, with the body showing the strongest correlations with frontal and parietal LL (p < 0.0001). The strong correlations between DTI indices in the CC and the extent of lesions in connected brain regions support the hypothesis that Wallerian degeneration of axons transected by remote, but connected focal lesions, is an important pathogenic mechanism of damage in MS.