Limbic and Callosal White Matter Changes in Euthymic Bipolar I Disorder: An Advanced Diffusion Magnetic Resonance Imaging Tractography Study
Limbic and Callosal White Matter Changes in Euthymic Bipolar I Disorder: An Advanced Diffusion Magnetic Resonance Imaging Tractography Study
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DOI：
10.1016/j.biopsych.2012.09.023
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发表时间：
2013-01-15
影响因子：
10.6
通讯作者：
McDonald, Colm
中科院分区：
文献类型：
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作者：
Emsell, Louise;Leemans, Alexander;McDonald, Colm
背景：在双相情感障碍中，已经报道了使用扩散张量成像检测到的白色物质微结构变化。然而，研究结果是异质的，这可能与使用的分析技术，不能充分模拟大脑中的交叉纤维。因此，我们试图使用改进的高角分辨率纤维跟踪技术来识别改变的扩散各向异性和扩散率变化。扩散磁共振成像数据来自35例前瞻性确认的情感正常的双相情感障碍1型患者（年龄22-59岁）和43名对照受试者（年龄22-59岁），这些受试者来自120个年龄和性别匹配的人口统计学上相似的病例对照对的样本。纤维束成像使用约束球面去卷积方法来解释交叉纤维。在胼胝体、扣带和穹窿的细分中，测量患者组和对照组之间的各向异性分数、平均扩散率、轴向扩散率和径向扩散率的变化，作为双相情感障碍中白色物质微结构组织的特征差异的指标。患者胼胝体各分区的各向异性分数显著降低，平均扩散率和径向扩散率增加，左侧穹窿和膝下扣带回与对照组相比。轴向扩散率增加，在穹窿双边和右背前cingulus.Conclusions：通过使用一种改进的纤维跟踪方法在临床同质的人口，我们能够本地化特质扩散率的变化，以特定的细分边缘纤维通路，包括穹窿。我们的研究结果扩展了以前的报道，即边缘系统微结构紊乱改变是双相情感障碍的一个特征
Background: White matter microstructural changes detected using diffusion tensor imaging have been reported in bipolar disorder. However, findings are heterogeneous, which may be related to the use of analysis techniques that cannot adequately model crossing fibers in the brain. We therefore sought to identify altered diffusion anisotropy and diffusivity changes using an improved high angular resolution fiber-tracking technique.Methods: Diffusion magnetic resonance imaging data was obtained from 35 prospectively confirmed euthymic bipolar disorder type 1 patients (age 22-59) and 43 control subjects (age 22-59) drawn from a sample of 120 age- and gender-matched demographically similar case-control pairs. Tractography using a constrained spherical deconvolution approach to account for crossing fibers was implemented. Changes in fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity between patient and control groups in subdivisions of the corpus callosum, cingulum, and fornix were measured as indicators of trait differences in white matter microstructural organization in bipolar disorder.Results: Patients had significantly reduced fractional anisotropy and increased mean diffusivity and radial diffusivity in all divisions of the corpus callosum, left fornix, and subgenual cingulum compared with control subjects. Axial diffusivity was increased in the fornix bilaterally and right dorsal-anterior cingulum.Conclusions: By using an improved fiber-tracking method in a clinically homogeneous population, we were able to localize trait diffusivity changes to specific subdivisions of limbic fiber pathways, including the fornix. Our findings extend previous reports of altered limbic system microstructural disorganization as a trait feature of bipolar disorder