Asymptomatic COVID-19 and structural changes in the brain

Abstract

Aims: Neurological symptoms are the most prevalent extrapulmonary complications of coronavirus disease 2019 (COVID-19). In this context, the objective of this study is to assess the brain magnetic resonance imaging (MRI) parameters of asymptomatic COVID-19 individuals one year after diagnosed with COVID-19 in comparison with healthy control subjects. Methods: The population of this prospective study consisted of individuals who have not developed olfactory impairment or other complications within one year after diagnosed with COVID-19. For the study, 8 male, 25 female, 4 male and 23 female individuals were accepted for PCG and CG, respectively, according to the inclusion and exclusion criteria. The mean age was found to be 37.75±11.56 and 37.11±10.67, respectively. All participants included in the study underwent olfactory sulcus (OS) depth, olfactory bulb (OB) volume, hippocampal sclerosis (HS), insular gyrus area, and corpus amygdala area measurements. Results: The bilateral OB volume, insular gyrus area and corpus amygdala area were significantly lower in the post-COVID-19 group (PCG) than in the control group (CG) (p<0.05). On the other hand, the bilateral OS depth was significantly higher in PCG than in CG (p<0.05). In the PCG, the insular gyrus area and corpus amygdala area values of the right side were significantly higher than those of the left side (p<0.05). In addition, bilateral HS was detected in five patients in the PCG, right-sided HS in two patients, and left-sided HS in one patient. Conclusion: The findings of this study have shown that COVID-19 infection, albeit asymptomatic, can trigger neurodegeneration. We believe that in the future COVID-19 infection will play a role in the etiopathogenesis of many neurodegenerative diseases.