## 3 Results
### Regional Differences in the Percentage Signal Change  
The unadjusted global mean CVR values were slightly lower in the PCS\({}_{\text{fmc}}\) subgroup (0.83 \(\pm\) 0.34%) than in the PCS\({}_{\text{mn}}\) subgroup (0.84 \(\pm\) 0.22%) and in the control group (0.92 \(\pm\) 0.27%) (see Table 2). After adjustment for age, time since infection, the Fazekas score, and the global CVR values were also slightly lower in the PCS\({}_{\text{fmc}}\) subgroup (0.78 \(\pm\) 0.11%) and in the PCS\({}_{\text{mn}}\) subgroup (0.84 \(\pm\) 0.10%) than in the control group (0.87 \(\pm\) 0.07%) (see Table 2 and Figure 2). The observed CVR differences between the subgroups after adjustment for age, time since infection, and Fazekas score were not statistically significant: \(F(2,\,25)\) = 0.21, \(p\) = 0.81, and partial \(\eta^{2}\) = 0.02. There was no significant interaction between subgroup assignment and sex: \(F(2,\,25)\) = 0.19, \(p\) = 0.83, and partial \(\eta^{2}\) = 0.02. The unadjusted and adjusted mean CVR values of each ROI are shown in Table 2. After adjustment for age, time since infection and Fazekas score, statistically significant differences in mean CVR were not found between the PCS subgroups and the healthy controls in any ROI: frontal lobe, \(F(2,\,25)\) = 0.58, \(p\) = 0.57, partial \(\eta^{2}\) = 0.05; occipital lobe, \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & **Patients with PCS\({}_{\text{fmc}}\) 1** & **Patients with PCS\({}_{\text{mn}}\) 2** & \multicolumn{3}{c}{**Health Subjects with Previous**} \\  & **Before PSM 3** & **After PSM 3** & **Before PSM 3** & **After PSM 3** & **Before PSM 3** & **After PSM 3** \\ \hline
**Number of persons** & 14 & 9 & 11 & 8 & 17 & 17 \\ \hline
**Female/male ratio** & 6.0:1 & 3.5:1 & 1.8:1 & 1.7:1 & 2.4:1 & 2.4:1 \\ \hline
**Mean age [years] (SD)** & 38.9 (9.9) & 38.7 (2.7) & 41.1 (7.6) & 37.8 (2.5) & 32.9 (6.3) & 33.9 (2.3) \\ \hline
**Time after** & & & & & & \\
**SARS-CoV-2 infection** & 22.6 (8.4) & 21.1 (2.9) & 21.4 (10.9) & 19.8 (4.0) & 19.7 (2.4) & 19.7 (2.4) \\
**[months] (SD)** & & & & & & \\ \hline
**Fazekas score (SD)** & 0.2 (0.1) & 0.2 (0.2) & 0.7 (0.2) & 0.6 (0.3) & 0.2 (0.1) & 0.2 (0.1) \\ \hline \hline \end{tabular}  
* \({}^{1}\) PCS\({}_{\text{fmc}}\) = Post-COVID-19 syndrome with leading symptoms of fatigue/memory issues/concentration disorder.
* \({}^{2}\) PCS\({}_{\text{mn}}\) = Post-COVID-19 syndrome with leading symptoms of myopathy/neuropathy. 3 PSM = propensity score matching.  
\end{table} 
Table 1: General patient data. \(F(2,\,25)=0.34\), \(p=0.71\), partial \(\eta^{2}=0.03\); parietal lobe, \(F(2,\,25)=0.56\), \(p=0.95\), partial \(\eta^{2}=0.00\); temporal lobe \(F(2,\,25)=0.57\), \(p=0.57\), partial \(\eta^{2}=0.04\); limbic system \(F(2,\,25)=0.60\), \(p=0.56\), partial \(\eta^{2}=0.05\); basal ganglia and thalamus \(F(2,\,25)=0.27\), \(p=0.77\), partial \(\eta^{2}=0.02\); and cerebellum \(F(2,\,25)=0.29\), \(p=0.75\), partial \(\eta^{2}=0.02\). No significant interactions between the subgroup assignments and sex were observed: frontal lobe, \(F(2,\,25)=0.29\), \(p=0.75\), partial \(\eta^{2}=0.02\); occipital lobe, \(F(2,\,25)=0.20\), \(p=0.81\), partial \(\eta^{2}=0.02\); parietal lobe, \(F(2,\,25)=0.76\), \(p=0.48\), partial \(\eta^{2}=0.06\); temporal lobe \(F(2,\,25)=0.30\), \(p=0.75\), partial \(\eta^{2}=0.02\); limbic system \(F(2,\,25)=0.10\), \(p=0.90\), partial \(\eta^{2}=0.01\); basal ganglia and thalamus \(F(2,\,25)=0.04\), \(p=0.97\), partial \(\eta^{2}=0.00\); and cerebellum \(F(2,\,25)=0.01\)\(p=1.00\), partial \(\eta^{2}=0.00\).