Abstract：
Between 2.5 and 28% of people infected with SARS-CoV-2 suffer Long COVID or persistence of symptoms for months after acute illness. Many symptoms are neurological, but the brain changes underlying the neuropsychological impairments remain unclear. This study aimed to provide a detailed description of the cognitive profile, the pattern of brain alterations in Long COVID and the potential association between them. To address these objectives, 83 patients with persistent neurological symptoms after COVID-19 were recruited, and 22 now healthy controls chosen because they had suffered COVID-19 but did not experience persistent neurological symptoms. Patients and controls were matched for age, sex and educational level. All participants were assessed by clinical interview, comprehensive standardized neuropsychological tests and structural MRI. The mean global cognitive function of patients with Long COVID assessed by ACE III screening test (Overall Cognitive level - OCLz= -0.39± 0.12) was significantly below the infection recovered-controls (OCLz= +0.32± 0.16, p< 0.01). We observed that 48% of patients with Long COVID had episodic memory deficit, with 27% also impaired overall cognitive function, especially attention, working memory, processing speed and verbal fluency. The MRI examination included grey matter morphometry and whole brain structural connectivity analysis. Compared to infection recovered controls, patients had thinner cortex in a specific cluster centred on the left posterior superior temporal gyrus. In addition, lower fractional anisotropy (FA) and higher radial diffusivity (RD) were observed in widespread areas of the patients\' cerebral white matter relative to these controls. Correlations between cognitive status and brain abnormalities revealed a relationship between altered connectivity of white matter regions and impairments of episodic memory, overall cognitive function, attention and verbal fluency. This study shows that patients with neurological Long COVID suffer brain changes, especially in several white matter areas, and these are associated with impairments of specific cognitive functions.
摘要：
感染SARS-CoV-2的人中有2.5％至28％的人在急性疾病后数月患有长期COVID或持续症状。许多症状是神经系统的，但是神经心理障碍背后的大脑变化仍不清楚。这项研究旨在提供对认知概况的详细描述，长型COVID的大脑改变模式及其之间的潜在关联。为了实现这些目标，招募了83例COVID-19后神经症状持续的患者，选择了22名健康对照，因为他们患有COVID-19，但没有出现持续的神经系统症状。患者和对照组的年龄相匹配，性别和教育水平。所有参与者都通过临床访谈进行评估，全面的标准化神经心理学测试和结构MRI。通过ACEIII筛查测试评估的长型COVID患者的平均整体认知功能（总体认知水平-OCLz=-0.39±0.12）显着低于感染恢复对照（OCLz=0.32±0.16，p<0.01）。我们观察到48％的长COVID患者有情景记忆缺陷，27%的人还损害了整体认知功能，特别注意,工作记忆,处理速度和语言流畅性。MRI检查包括灰质形态测量和全脑结构连接分析。与感染恢复的对照相比，患者在以左颞上回为中心的特定簇中具有较薄的皮质。此外,相对于这些对照,在患者脑白质的广泛区域观察到较低的各向异性分数(FA)和较高的径向扩散率(RD).认知状态与大脑异常之间的相关性揭示了白质区域连通性改变与情景记忆受损之间的关系，整体认知功能，注意力和口头流畅性。这项研究表明，患有神经系统长型COVID的患者会发生大脑变化，特别是在几个白质区域，这些与特定认知功能的损害有关。
