Importance Persistent depressive symptoms, often accompanied by cognitive symptoms, commonly occur after COVID-19 illness (hereinafter termed COVID-DC, DC for depressive and/or cognitive symptoms). In patients with COVID-DC, gliosis, an inflammatory change, was suspected, but measurements of gliosis had not been studied in the brain for this condition. Objective To determine whether translocator protein total distribution volume (TSPO VT), a marker of gliosis that is quantifiable with positron emission tomography (PET), is elevated in the dorsal putamen, ventral striatum, prefrontal cortex, anterior cingulate cortex, and hippocampus of persons with COVID-DC. Design, Setting, and Participants This case-control study conducted at a tertiary care psychiatric hospital in Canada from April 1, 2021, to June 30, 2022, compared TSPO VT of specific brain regions in 20 participants with COVID-DC with that in 20 healthy controls. The TSPO VT was measured with fluorine F 18-labeled N-(2-(2-fluoroethoxy)benzyl)-N-(4-phenoxypyridin-3-yl)acetamide ([18F]FEPPA) PET. Main Outcomes and Measures The TSPO VT was measured in the dorsal putamen, ventral striatum, prefrontal cortex, anterior cingulate cortex, and hippocampus. Symptoms were measured with neuropsychological and psychological tests, prioritizing outcomes related to striatal function. Results The study population included 40 participants (mean [SD] age, 32.9 [12.3] years). The TSPO VT across the regions of interest was greater in persons with COVID-DC (mean [SD] age, 32.7 [11.4] years; 12 [60%] women) compared with healthy control participants (mean [SD] age, 33.3 [13.9] years; 11 [55%] women): mean (SD) difference, 1.51 (4.47); 95% CI, 0.04-2.98; 1.51 divided by 9.20 (17%). The difference was most prominent in the ventral striatum (mean [SD] difference, 1.97 [4.88]; 95% CI, 0.36-3.58; 1.97 divided by 8.87 [22%]) and dorsal putamen (mean difference, 1.70 [4.25]; 95% CI, 0.34-3.06; 1.70 divided by 8.37 [20%]). Motor speed on the finger-tapping test negatively correlated with dorsal putamen TSPO VT (r, -0.53; 95% CI, -0.79 to -0.09), and the 10 persons with the slowest speed among those with COVID-DC had higher dorsal putamen TSPO VT than healthy persons by 2.3 (2.30 divided by 8.37 [27%]; SD, 2.46; 95% CI, 0.92-3.68). Conclusions and Relevance In this case-control study, TSPO VT was higher in patients with COVID-DC. Greater TSPO VT is evidence for an inflammatory change of elevated gliosis in the brain of an individual with COVID-DC. Gliosis may be consequent to inflammation, injury, or both, particularly in the ventral striatum and dorsal putamen, which may explain some persistent depressive and cognitive symptoms, including slowed motor speed, low motivation or energy, and anhedonia, after initially mild to moderate COVID-19 illness.

中文翻译：

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COVID-19 后的神经炎症伴有持续的抑郁和认知症状。

重要性 持续性抑郁症状，通常伴有认知症状，通常发生在 COVID-19 患病后（以下称为“COVID-DC”，DC 表示抑郁和/或认知症状）。在 COVID-DC 患者中，怀疑存在神经胶质增生（一种炎症变化），但尚未针对这种情况在大脑中研究神经胶质增生的测量结果。目的 确定易位蛋白总分布体积 (TSPO VT)（一种可通过正电子发射断层扫描 (PET) 量化的神经胶质增生标志物）在人的背壳核、腹侧纹状体、前额叶皮层、前扣带皮层和海马中是否升高与新冠肺炎 (COVID-DC) 一起。设计、设置和参与者 这项病例对照研究于 2021 年 4 月 1 日至 2022 年 6 月 30 日在加拿大一家三级精神病院进行，比较了 20 名 COVID-DC 参与者与 20 名参与者特定大脑区域的 TSPO VT。健康的控制。使用氟F 18 标记的N-(2-(2-氟乙氧基)苄基)-N-(4-苯氧基吡啶-3-基)乙酰胺([ 18 F]FEPPA)PET测量TSPO VT。主要结果和措施 TSPO VT 测量于背壳核、腹侧纹状体、前额皮质、前扣带皮层和海马。通过神经心理学和心理测试来测量症状，优先考虑与纹状体功能相关的结果。结果 研究人群包括 40 名参与者（平均 [SD] 年龄，32.9 [12.3] 岁）。与健康对照参与者（平均 [SD] 年龄，33.3 [SD] 岁）相比，COVID-DC 患者（平均 [SD] 年龄，32.7 [11.4] 岁；12 [60%] 女性）跨感兴趣区域的 TSPO VT 更大。 13.9] 岁；11 [55%] 女性）：平均 (SD) 差异，1.51 (4.47)；95% CI，0.04-2.98；1.51 除以 9.20 (17%)。差异在腹侧纹状体（平均 [SD] 差异，1.97 [4.88]；95% CI，0.36-3.58；1.97 除以 8.87 [22%]）和背壳核（平均差异，1.70 [4.25]； 95% CI，0.34-3.06；1.70 除以 8.37 [20%]）。手指敲击测试的运动速度与背壳核 TSPO VT 呈负相关（r，-0.53；95% CI，-0.79 至 -0.09），并且在 COVID-DC 患者中速度最慢的 10 人具有较高的背壳核TSPO VT 比健康人高 2.3（2.30 除以 8.37 [27%]；SD，2.46；95% CI，0.92-3.68）。结论和相关性 在这项病例对照研究中，COVID-DC 患者的 TSPO VT 较高。更大的 TSPO VT 是 COVID-DC 患者大脑中神经胶质增生升高的炎症变化的证据。神经胶质增生可能是炎症、损伤或两者兼而有之的结果，特别是在腹侧纹状体和背壳核中，这可能解释了一些持续的抑郁和认知症状，包括运动速度减慢、动机或能量低下以及快感缺乏，在最初轻度至中度的新冠病毒感染后-19 疾病。