Keramatian Kamyar, Chakrabarty Trisha, Saraf Gayatri, Pinto Jairo V, Yatham Lakshmi N
Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.
Department of Psychiatry, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
Bipolar Disord. 2021 May;23(3):228-240. doi: 10.1111/bdi.12995. Epub 2020 Oct 8.
It has been proposed that different stages of bipolar disorder may be underpinned by distinct neurobiological substrates. However, structural neuroimaging studies in early stages of the illness are limited by small sample sizes yielding inconsistent findings. The purpose of this systematic review and meta-analysis, therefore, was to identify regional grey matter volume (GMV) changes that are consistently associated with first episode of mania (FEM).
Following PRISMA guidelines, we conducted a systematic search of the literature to identify Voxel-Based Morphometry (VBM) studies in FEM patients compared with healthy individuals. We then conducted a voxel-wise meta-analysis using Seed-based d-Mapping technique. Finally, we performed univariate meta-regression analyses to explore the potential effects of moderator variables including age, gender, and percentage of lithium users on GMV alterations.
We identified 15 VBM studies and included 12 studies in the meta-analysis. Four studies found no regional differences in GM volumes while other 11 studies reported volume changes in frontal and temporal regions as well as anterior cingulate cortex (ACC), cerebellum and basal ganglia. The meta-analysis revealed a single cluster of GMV reduction in bilateral pregenual ACC in patients with FEM compared to healthy individuals (P < .001). The Egger's test showed no evidence of publication bias at peak voxel level (P = .447). Meta-regression analyses revealed no significant effects of moderators evaluated.
Structural brain changes are evident in the early stages of bipolar disorder. GMV reduction in bilateral pregenual ACC is the most consistent finding in VBM studies of FEM.
有人提出双相情感障碍的不同阶段可能由不同的神经生物学基质所支撑。然而，该疾病早期阶段的结构神经影像学研究受到样本量小的限制，结果不一致。因此，本系统评价和荟萃分析的目的是确定与首次躁狂发作（FEM）始终相关的区域灰质体积（GMV）变化。
按照PRISMA指南，我们对文献进行了系统检索，以确定与健康个体相比的FEM患者的基于体素的形态计量学（VBM）研究。然后，我们使用基于种子的d映射技术进行了体素水平的荟萃分析。最后，我们进行了单变量荟萃回归分析，以探讨调节变量（包括年龄、性别和锂使用者百分比）对GMV改变的潜在影响。
我们确定了15项VBM研究，并将12项研究纳入荟萃分析。4项研究未发现灰质体积的区域差异，而其他11项研究报告了额叶、颞叶区域以及前扣带回皮质（ACC）、小脑和基底神经节的体积变化。荟萃分析显示，与健康个体相比，FEM患者双侧膝前ACC的GMV减少单一聚类（P <.001）。Egger检验在峰值体素水平未显示发表偏倚的证据（P =.447）。荟萃回归分析显示所评估的调节变量无显著影响。
双相情感障碍早期阶段脑结构变化明显。双侧膝前ACC的GMV减少是FEM的VBM研究中最一致的发现。
