Objective: To explore the characteristics of cortical morphology in cerebral small vessel disease (CSVD) patients with subcortical ischemic depression (SID) and its relationship with clinical symptoms. Methods: A total of 88 patients with CSVD in the First Affiliated Hospital of Anhui Medical University were enrolled from July 2017 to July 2020. The subjects were divided into CSVD-non depression group (CSVD-ND, n=58) and SID group (n=30) according to the geriatric depression scale (GDS). The 3D-T1 MRI images were obtained from all subjects. The computed anatomy toolbox 12 (CAT 12) was used for image processing and cortical segmentation to obtain the cortical thickness (CTh) and surface metrics, including gyrification index (GI), sulcus depth (SD) and fractal dimension (FD). A comparison at the vertex- and region-of-interest (ROI)-wise levels were performed by the general linear model, and correlation analysis were conducted between cortical morphometric measurements and GDS scores. Finally, mean CTh (mCTh) was extracted for binary logistic regression analysis. Results: At the vertex-wise level, compared with the CSVD-ND group, the SID patients showed increased CTh in clusters mainly located in the posterior default mode network (pDMN), such as the precuneus(Pcu), the superior parietal gyrus (SPG) and the right postcentral gyrus (PoCG). As for the surface measurements, the GI value and the FD value were increased in clusters of Pcu and inferior temporal gyrus (ITG), respectively, in the SID group. ROIs analyses showed that apart from the Pcu, the SPG and the right PoCG, CTh alterations in the SID group were involved in a wider range of regions, extending to the right precentral gyrus ((2.27±0.20) cm3 vs (2.12±0.26) cm3, P=0.007), the left paracentral gyrus ((2.18±0.20) cm3 vs (2.05±0.23) cm3, P=0.008) and so on, than that in the CSVD-ND group.Compared with the CSVD-ND patients, the SID patients showed increased GI in the right PoCG ((25.31±1.11) vs (24.23±1.27), P<0.05). Correlation analysis showed that CTh in the right Pcu was positively correlated with the GDS scores (r=0.4, P<0.05). Further binary logistic regression analysis showed that in comparison with the subjects in the reference group (<2.367 cm3), the odds ratio(95%CI) for SID patients in the highest tertile of mCTh (>2.473 cm3) were 6.373 (1.254-32.389) after multivariable adjustment (sex, age, years of education, total intracranial volume, traditional imaging findings of CSVD, cognitive function (CAMCOG-C) and mCTh). Conclusion: Both CTh and cortical complexity were increased in CSVD patients with SID, especially in the clusters of pDMN, and CTh may be an important risk factor for SID.
目的： 探讨脑小血管病（CSVD）患者皮质下缺血性抑郁（SID）的脑皮质形态学改变特点及其与临床症状的相关性。 方法： 研究纳入2017年7月至2020年7月于安徽医科大学第一附属医院门诊和住院收治的CSVD患者88例，根据老年抑郁量表（GDS）评分分为CSVD非抑郁组（CSVD-ND， n=58）和抑郁组（SID， n=30），获取所有受试者磁共振3D-T1图像，应用计算解剖学工具箱（CAT 12）进行图像处理及皮质分割，获取皮质厚度（CTh）及皮质复杂度参数，包括脑回指数（GI）、沟深（SD）及分形维数（FD）；采用一般线性模型分别进行基于顶点和感兴趣区（ROI）的皮质结构比较，将皮质参数与GDS评分进行相关分析，同时提取全脑平均CTh（mCTh）纳入二项式logistic回归模型进行分析。 结果： 基于顶点分析发现，与CSVD-ND组相比，SID组在后默认网络（pDMN）脑区，如楔前叶（Pcu），顶上回（SPG）及右侧中央后回（PoCG）等脑区CTh显著增加（均P<0.001）；同时在Pcu脑区的GI值及颞下回（ITG）脑区的FD值均显著增加（均P<0.001）。基于ROI研究发现，与CSVD-ND组相比，SID患者CTh增加脑区除了Pcu、SPG及右侧PoCG外，进一步延伸至右侧中央前回［（2.27±0.20） cm3比（2.12±0.26） cm3，P=0.007］、左侧中央旁回［（2.18±0.20） cm3比（2.05±0.23） cm3，P=0.008］等更广泛的皮质区域；GI值在右侧PoCG脑区显著增加（25.31±1.11比24.23±1.27，P<0.05）。相关分析发现左侧Pcu脑区CTh与GDS评分呈正相关（r=0.4，P<0.05）；将性别、年龄、受教育年限、颅脑总体积、CSVD传统影像学表现、认知功能（CAMCOG-C）及mCTh等纳入二项式logistic回归模型，结果显示高mCTh组（>2.473 cm3）患SID的风险是低mCTh组（<2.367 cm3）的6.373倍（95%CI：1.254~32.389）。 结论： CSVD患者的SID脑CTh及皮质复杂度均显著增加，以pDMN脑区尤为明显；且CTh可能为SID的重要风险因素。.