目的:探讨COVID-19相关持续性嗅觉功能障碍(OD)患者的神经心理学特征和嗅觉网络的完整性。
方法:持续COVID-19相关OD的患者接受Sniffin棒和神经心理学评估的嗅觉评估。此外,患者和对照组都接受了脑部MRI检查,包括3T扫描仪上的T1加权和静息状态功能MRI(rs-fMRI)序列。在嗅觉相关区域评估了形态计量学特性;rs-fMRI数据是使用图论在全脑水平上和嗅觉功能网络的标准部分进行分析的。比较两组的所有MR衍生量,并探讨其与患者临床评分的相关性。
结果:我们纳入了23例患者(平均年龄37±14岁,12名女性)持续(平均持续时间11±5个月,范围2-19个月)COVID-19相关OD(平均得分为23.63±5.32/48,低血压临界值:30.75)和26名性别和年龄匹配的健康对照。应用人口派生的截止值,这两个认知领域主要受损的是视觉空间记忆和执行功能(17%和13%的患者).脑部MRI未显示大体形态异常。眶外侧皮层,海马体,杏仁核体积在患者中表现出减少的趋势,多重比较校正后不显著。患者和对照组的嗅球体积没有差异。功能性嗅觉网络的图形分析显示,与对照组相比,患者组的整体和局部特性发生了变化(n=19,由于伪影而排除4)。具体来说,我们检测到全局模块化系数的减小,与失足严重程度呈正相关,以及右丘脑功能连接的程度和强度的增加,与短期言语记忆得分呈负相关。
结论:患有持续COVID-19相关OD的患者显示嗅觉网络连接性改变,其与睡眠障碍严重程度和神经心理学表现相关。与对照组相比,患者未发现明显的形态学改变。
To explore the neuropsychological profile and the integrity of the olfactory network in patients with COVID-19-related persistent olfactory dysfunction (OD).
Patients with persistent COVID-19-related OD underwent olfactory assessment with Sniffin\' Sticks and neuropsychological evaluation. Additionally, both patients and a control group underwent brain MRI, including T1-weighted and resting-state functional MRI (rs-fMRI) sequences on a 3 T scanner. Morphometrical properties were evaluated in olfaction-associated regions; the rs-fMRI data were analysed using graph theory at the whole-brain level and within a standard parcellation of the olfactory functional network. All the MR-derived quantities were compared between the two groups and their correlation with clinical scores in patients were explored.
We included 23 patients (mean age 37 ± 14 years, 12 females) with persistent (mean duration 11 ± 5 months, range 2-19 months) COVID-19-related OD (mean score 23.63 ± 5.32/48, hyposmia cut-off: 30.75) and 26 sex- and age-matched healthy controls. Applying population-derived cut-off values, the two cognitive domains mainly impaired were visuospatial memory and executive functions (17 % and 13 % of patients). Brain MRI did not show gross morphological abnormalities. The lateral orbital cortex, hippocampus, and amygdala volumes exhibited a reduction trend in patients, not significant after the correction for multiple comparisons. The olfactory bulb volumes did not differ between patients and controls. Graph analysis of the functional olfactory network showed altered global and local properties in the patients\' group (n = 19, 4 excluded due to artifacts) compared to controls. Specifically, we detected a reduction in the global modularity coefficient, positively correlated with hyposmia severity, and an increase of the degree and strength of the right thalamus functional connections, negatively correlated with short-term verbal memory scores.
Patients with persistent COVID-19-related OD showed an altered olfactory network connectivity correlated with hyposmia severity and neuropsychological performance. No significant morphological alterations were found in patients compared with controls.