Department of Medical Imaging, Guangdong No.2 Provincial People's Hospital, Guangzhou, People's Republic of China.
PLoS One. 2013 May 1;8(5):e63212. doi: 10.1371/journal.pone.0063212. Print 2013.
To investigate the WM microstructure deficits in heroin dependent individuals (HDIs) with different length of heroin dependence, and to investigate whether these WM deficits can be related to the duration of heroin use and to decision-making deficits in HDIs.
METHODOLOGY/PRINCIPAL FINDINGS: Thirty-six HDIs [including eighteen sHDIs (duration of heroin dependent is less than 10 years) and eighteen lHDIs (duration of dependent is between 10:20 years)] and sixteen healthy controls participated in this study. Whole brain voxel-wise analysis of fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (Da) and radial diffusivity (Dr) were performed by tract-based spatial statistics (TBSS) to localize abnormal WM regions among groups. TBSS demonstrated that sHDIs had significantly lower FA than controls in right orbito-frontal WM, bilateral temporal WM and right parietal WM. The lHDIs had significantly lower FA throughout the brain compared with the controls and sHDIs. The lHDIs had significantly lower Da than controls in bilateral inferior frontaloccipital fasciculus, bilateral splenium of corpus callosum, left inferior longitudinal fasciculus, and had significantly higher Dr than controls in bilateral uncinatus fasciculus, bilateral inferior frontaloccipital fasciculus and bilateral cortical spinal fasciculus. Volume-of-interest (VOI) analyses detect the changes of diffusivity indices in the regions with FA abnormalities revealed by control vs sHDIs. In most VOIs, FA reductions were caused by the increase in Dr as well as the decrease in Da. Correlation analysis was used to assess the relationship between FA and behavioral measures in HDIs and controls available. Significantly positively correlations were found between the FA values in the right orbital-frontal WM, right parietal WM and IGT performance.
The extent and severity of WM integrity deficits in HDIs was associated with the length of heroin dependent. Furthermore, abnormal WM microstructure may correlate with decision-making impairments in HDIs.
为了探究不同海洛因依赖时间的海洛因依赖者（HDI）的 WM 微观结构缺陷，并探讨这些 WM 缺陷是否与海洛因使用时间有关，以及与 HDI 的决策缺陷有关。
方法/主要发现：36 名海洛因依赖者[包括 18 名 sHDI（海洛因依赖时间小于 10 年）和 18 名 lHDI（依赖时间在 10-20 年之间）]和 16 名健康对照者参与了这项研究。通过基于束的空间统计学（TBSS）对全脑各向异性分数（FA）、平均扩散系数（MD）、轴向扩散系数（Da）和径向扩散系数（Dr）进行了体素分析，以定位各组间异常 WM 区域。TBSS 显示，与对照组相比，sHDI 右侧眶额 WM、双侧颞 WM 和右侧顶叶 WM 的 FA 显著降低。与对照组和 sHDI 相比，lHDI 整个大脑的 FA 显著降低。与对照组相比，lHDI 在双侧下额枕束、双侧胼胝体压部、左侧下纵束的 Da 显著降低，在双侧钩束、双侧下额枕束和双侧皮质脊髓束的 Dr 显著升高。感兴趣区（VOI）分析检测到 FA 异常控制与 sHDI 之间区域扩散指数的变化。在大多数 VOI 中，FA 的降低是由于 Dr 的增加和 Da 的减少引起的。相关性分析用于评估 HDI 和对照组中 FA 与行为测量之间的关系。在右侧眶额 WM、右侧顶叶 WM 和 IGT 表现中发现 FA 值与行为测量之间存在显著正相关。
HDI 中 WM 完整性缺陷的程度和严重程度与海洛因依赖时间有关。此外，异常的 WM 微观结构可能与 HDI 的决策缺陷有关。
