Mamah Daniel, Patel Aakash, Chen ShingShiun, Wang Yong, Wang Qing
Department of Psychiatry, Washington University School of Medicine, 660 S. Euclid, Campus Box 8134, St. Louis, MO, 63110, USA.
Department of Obstetrics and Gynecology, Washington University School of Medicine, 4525 Scott Ave, Campus Box 8225, St. Louis, MO, 63110, USA.
Brain Imaging Behav. 2025 Jun 6. doi: 10.1007/s11682-025-01021-w.
Multiple studies point to the role of neuroinflammation in the pathophysiology of schizophrenia (SCZ), however, there have been few in vivo tools for imaging brain inflammation. Diffusion basis spectrum imaging (DBSI) is an advanced diffusion-based MRI method developed to quantitatively assess microstructural alternations relating to neuroinflammation, axonal fiber, and other white matter (WM) pathologies. We acquired one-hour-long high-directional diffusion MRI data from young control (CON, n = 27), schizophrenia (SCZ, n = 21), and bipolar disorder (BPD, n = 21) participants aged 18-30. We applied Tract-based Spatial Statistics (TBSS) to allow whole-brain WM analyses and compare DBSI-derived isotropic and anisotropic diffusion measures between groups. Clinical relationships of DBSI metrics with clinical symptoms were assessed across SCZ and control participants. In SCZ participants, we found a generalized increase in DBSI-derived cellularity (a putative marker of neuroinflammation), a decrease in restricted fiber fraction (a putative marker of apparent axonal density), and an increase in extra-axonal water (a putative marker of vasogenic edema) across several WM tracts. There were only minimal WM abnormalities noted in BPD, mainly in regions of the corpus callosum (increase in DTI-derived RD and extra-axonal water). DBSI metrics showed significant partial correlations with psychosis and mood symptoms across groups. Our findings suggest that SCZ involves generalized white matter neuroinflammation, decreased fiber density, and demyelination, which is not seen in bipolar disorder. Larger studies are needed to identify medication-related effects. DBSI metrics could help identify high-risk groups requiring early interventions to prevent the onset of psychosis and improve outcomes.
多项研究指出神经炎症在精神分裂症（SCZ）病理生理学中的作用，然而，用于脑部炎症成像的体内工具却很少。扩散基谱成像（DBSI）是一种先进的基于扩散的磁共振成像方法，旨在定量评估与神经炎症、轴突纤维及其他白质（WM）病变相关的微观结构改变。我们采集了年龄在18至30岁之间的年轻对照组（CON，n = 27）、精神分裂症患者（SCZ，n = 21）和双相情感障碍患者（BPD，n = 21）长达一小时的高定向扩散磁共振成像数据。我们应用基于纤维束的空间统计学（TBSS）进行全脑白质分析，并比较各组之间DBSI衍生的各向同性和各向异性扩散测量值。在SCZ患者和对照参与者中评估了DBSI指标与临床症状的临床关系。在SCZ患者中，我们发现多个白质束中DBSI衍生的细胞密度（一种推测的神经炎症标志物）普遍增加，受限纤维分数（一种推测的表观轴突密度标志物）降低，以及轴突外水（一种推测的血管源性水肿标志物）增加。在BPD中仅发现极少的白质异常，主要在胼胝体区域（DTI衍生的RD和轴突外水增加）。DBSI指标在各组中均显示出与精神病和情绪症状的显著部分相关性。我们的研究结果表明，SCZ涉及全身性白质神经炎症、纤维密度降低和脱髓鞘，而双相情感障碍中未见此现象。需要更大规模的研究来确定药物相关影响。DBSI指标有助于识别需要早期干预以预防精神病发作并改善预后的高危人群。
