Universidade Federal do ABC, Santo André, Brazil.
J Psychiatr Res. 2012 Sep;46(9):1126-32. doi: 10.1016/j.jpsychires.2012.05.008. Epub 2012 Jun 8.
Several recent studies in literature have identified brain morphological alterations associated to Borderline Personality Disorder (BPD) patients. These findings are reported by studies based on voxel-based-morphometry analysis of structural MRI data, comparing mean gray-matter concentration between groups of BPD patients and healthy controls. On the other hand, mean differences between groups are not informative about the discriminative value of neuroimaging data to predict the group of individual subjects. In this paper, we go beyond mean differences analyses, and explore to what extent individual BPD patients can be differentiated from controls (25 subjects in each group), using a combination of automated-morphometric tools for regional cortical thickness/volumetric estimation and Support Vector Machine classifier. The approach included a feature selection step in order to identify the regions containing most discriminative information. The accuracy of this classifier was evaluated using the leave-one-subject-out procedure. The brain regions indicated as containing relevant information to discriminate groups were the orbitofrontal, rostral anterior cingulate, posterior cingulate, middle temporal cortices, among others. These areas, which are distinctively involved in emotional and affect regulation of BPD patients, were the most informative regions to achieve both sensitivity and specificity values of 80% in SVM classification. The findings suggest that this new methodology can add clinical and potential diagnostic value to neuroimaging of psychiatric disorders.
几项最近的文献研究已经确定了与边缘型人格障碍(BPD)患者相关的大脑形态变化。这些发现是基于基于结构 MRI 数据的体素形态计量学分析的研究报告的,比较了 BPD 患者组和健康对照组之间的平均灰质浓度。另一方面,组间的平均差异对于预测个体受试者群体的神经影像学数据的判别价值没有信息意义。在本文中,我们超越了均值差异分析,探索了使用组合自动形态计量工具进行区域皮质厚度/体积估计和支持向量机分类器,在多大程度上可以将个体 BPD 患者与对照组区分开来(每组 25 名受试者)。该方法包括特征选择步骤,以确定包含最具判别信息的区域。使用留一受试者法评估了此分类器的准确性。被指示为包含区分组信息的大脑区域是眶额、额前扣带回、后扣带回、颞中皮质等。这些区域在情绪和 BPD 患者的情感调节中明显参与,是实现 SVM 分类的敏感性和特异性值均为 80%的最具信息量的区域。这些发现表明,这种新方法可以为精神障碍的神经影像学增加临床和潜在的诊断价值。