基于弥散张量成像技术的双相障碍患者脑白质纤维束异常分析

Diffusion tensor imaging white matter fiber bundles in unmedicated bipolar disorder

目的探讨抑郁期双相障碍患者脑白质纤维束的变化。方法选取42例未用药双相障碍抑郁期患者(患者组)和年龄、性别及右利手与之相匹配的59名对照者(对照组)进行DTI检查,根据约翰霍普金斯大学人类白质纤维束图谱,将大脑白质组织分割为20条公认存在的粗大纤维束,应用PANDA软件计算每个被试者每条白质纤维束的4项平均弥散属性,采用非参数置换检验比较2组在20条白质纤维束上弥散指标的差异,将差异有统计学意义的脑白质纤维束弥散指标与临床指标进行Pearson相关分析。结果患者组左侧钩束各向异性分数(fractional anisotropy,FA)值低于对照组(0.40±0.01与0.41±0.01,P=0.001);胼胝体辐射线额部FA值低于对照组(0.36±0.02与0.38±0.02,P<0.001);左侧钩束径向弥散率(radial diffusivity,RD)值高于对照组(6.57×10^-4±2.41×10^-5与6.40×10^-4±2.42×10^-5,P=0.0017)。Pearson相关分析显示,2组弥散指标差异有统计学意义的白质纤维束与临床指标之间均无相关性。结论抑郁期双相障碍患者钩束及胼胝体辐射线额部存在脑白质完整性破坏。

Objective To investigate the changes of white matter fiber bundles in patients with bipolar disorder depressive epoch.Methods Forty-two patients with unmedicated bipolar disorder(BD)depression and 59 age-,sex-and handedness-matched healthy controls who underwent DTI were recruited in the study.According to the Johns Hopkins University human white matter fiber bundle map,the white matter tissue of the brain was segmented into 20 acknowledged large fiber bundles.The PANDA software was used to calculate the four average diffusion properties of each white matter fiber bundle for each subject.Nonparametric substitution test was used to detect the difference of diffusion index between the two groups on these 20 white matter fiber bundles.Pearson correlation analysis was performed between FA values and RD values extracted from significantly different white matter fiber bundles and clinical indices.Results In comparison to the normal controls,BD patients had a significant decreased fractional anisotropy(FA)values in the left uncinate fasciculus(0.40±0.01 vs.0.41±0.01,P=0.001)and the forceps minor(0.36±0.02 vs.0.38±0.02,P<0.001).Additionally,the radial diffusivity values increased in the left uncinate fasciculus(6.57×10^-4±2.41×10^-5vs.6.40×10^-4±2.42×10^-5,P=0.0017).Pearson correlation analysis showed that there were no significant correlations among the clinical indices the FA values and AD values in the left uncinate fasciculus and forceps minor.Conclusions The patients with bipolar disorder in depression possibly have abnormal left uncinate fasciculus and the forceps minor.