Changes in morphometric and neurochemical parameters of brain structure in patients with post-COVID syndrome

Post-COVID syndrome is poorly defined complex of different symptoms predominantly functional disorders, which are diagnosed in 30–70 % of patients after COVID-19 infection. To determine the pathogenic basis of neurological symptoms of post-COVID syndrome 105 patients (48 men, 40 women, mean age 47 [40; 54.5]) with post-COVID syndrome in the period from 3 months after COVID-infection and 10 people of the control group (4 men, 6 women, mean age 40 [28; 50]) were examined using structural magnetic resonance imaging (MRI) and magnetic resonance spectroscopy. After dividing of post-COVID patients group into three subgroups according to the severity of complaints no significant morphological differences in brain structures were determined according to MRI data. However was revealed interhemispheric asymmetry as the cerebral cortex thinning in left frontal lobe ( p = 0.006) and higher left temporal horn of the side ventricle ( p = 0.007) in subgroup post COVID patients with severity symptoms. Was revealed decrease of the N-acetylaspartate/creatinine (NAA/Cr) ratio in the anterior part of the cingulate gyrus on both sides ( p = 0.025 on the right, p = 0.025 on the left) and in the center semiovale on the right sides ( p = 0.001), an increase of choline/creatinine (Cho/Cr) ratio in the anterior cingulate gyrus on both sides ( p < 0.01 on the right) and ( p = 0.04 on the left), right next to areas of decreased NAA/Cr ratio. It was also revealed decrease of the myoinositol/creatinine ratio in the center semiovale area on the right ( p = 0.038) and the middle cingulate gyrus on the left ( p = 0.027). According to the functional topography of the brain neuromediation changes in the anterior cingulate gyrus and center semiovale may have clinical correlates as impaired executive functions, memory and mood disturbance what is related to post-COVID syndrome. Thus we found that neurological symptoms of post-COVID syndrome are based on multidirectional changes in the secretion of NAA and Cho in the cingulate gyrus of the brain without accompanying morphological pathology.