Discrete Neuroimaging Metrics for Identifying Structural Alterations in COVID-19-Related Brain Atrophy

Abstract

Several studies have evidenced the effects of SARS-CoV-2 on the central nervous system. In some cases, neurological symptoms have manifested with medium- to long-term persistence, suggesting the presence of brain damage. Our objective is to evaluate discrete tortuosity (T_d) and discrete compactness (C_d) as potential imaging biomarkers to quantify atrophic alterations caused by the pathology in various cerebral structures. T1-weighted magnetic resonance images were utilized to compare brain morphologies between 316 recovered COVID-19 patients and 316 matched controls, all over 60 years old. Morphological biomarkers, including T_d, C_d, volume (V), and mean cortical thickness (M_ct), were then applied to assess structural changes in different brain regions. Compared to controls, results for the COVID-19 patients showed a statistically significant (p < 0.05) increase in T_d and a decrease in C_d within the left cerebral cortex, left temporal lobe, left lateral orbitofrontal cortex, and left superior temporal gyrus, while the V and M_ct metrics showed non-significant reductions in the same structures. A statistically significant decrease in M_ct was observed in the right frontal lobe and left inferior temporal gyrus. Our results showed an increase in cortical gray matter atrophy in COVID-19 patients, potentially linked to neurodegenerative processes, with a greater prevalence in the left hemisphere. These findings suggest that T_d and C_d are sensitive metrics for detecting subtle atrophic changes and may complement traditional measures, which could enhance the assessment of SARS-CoV-2-associated brain alterations.