Cheng Chia-Hsin, Alshelh Zeynab, Guan Yi, Sullivan Kimberly, Loggia Marco L, Koo Bang-Bon
School of Medicine, Boston University, Boston, MA, USA.
Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.
Brain Behav Immun Health. 2021 Oct 6;18:100364. doi: 10.1016/j.bbih.2021.100364. eCollection 2021 Dec.
About a third of all United States veterans who served in the 1991 Gulf War (GW) report a range of chronic health symptoms including fatigue, neurocognitive symptoms, and musculoskeletal pain. There is growing evidence supporting the detrimental effects of maladaptive neuroimmune reactions in this multi-symptom illness. Indeed, recent studies using positron emission tomography (PET) using the radioligand [C]PBR28, which binds the neuroinflammation marker 18 kDa translocator protein (TSPO), and diffusion magnetic resonance imaging (dMRI) have independently identified the anterior cingulate (ACC) and midcingulate cortices (MCC) as key regions for differentiating GWI veterans from healthy controls (HC). Here, we used integrated (i.e., simultaneous) PET/MRI imaging techniques, paired with dMRI processing methods (neurite density imaging, NDI, and free-water diffusion tensor model to single-shell high-order dMRI), to directly evaluate the relationship between ACC and MCC microstructural tissue parameters, TSPO signal and clinical parameters in the same cohorts of 10 GWI veterans and 19 HCs. Within the regions evaluated, TSPO signal elevations were associated with restricted diffusivity in the extracellular compartment, while clinical measures were best explained by neurite density and cellular structure complexity measures. Our study is the first to provide evidence of a relationship between PET and dMRI modalities in GWI and suggests that microstructural changes in the ACC and MCC are correlated to mood symptoms and cognitive performances in GWI veterans.
在1991年海湾战争（GW）中服役的所有美国退伍军人中，约三分之一报告了一系列慢性健康症状，包括疲劳、神经认知症状和肌肉骨骼疼痛。越来越多的证据支持这种多症状疾病中适应不良的神经免疫反应的有害影响。事实上，最近使用放射性配体[C]PBR28进行正电子发射断层扫描（PET）的研究，该配体与神经炎症标志物18 kDa转运蛋白（TSPO）结合，以及扩散磁共振成像（dMRI），已独立确定前扣带回（ACC）和中扣带回皮质（MCC）是区分海湾战争疾病退伍军人与健康对照（HC）的关键区域。在这里，我们使用集成（即同时）PET/MRI成像技术，结合dMRI处理方法（神经突密度成像、NDI和单壳高阶dMRI的自由水扩散张量模型），直接评估10名海湾战争疾病退伍军人和19名健康对照的同一队列中ACC和MCC微观结构组织参数、TSPO信号和临床参数之间的关系。在所评估的区域内，TSPO信号升高与细胞外间隙的扩散受限有关，而临床测量结果最好由神经突密度和细胞结构复杂性测量来解释。我们的研究首次提供了海湾战争疾病中PET和dMRI模式之间关系的证据，并表明ACC和MCC的微观结构变化与海湾战争疾病退伍军人的情绪症状和认知表现相关。
