Effect of Post-COVID-19 on Brain Volume and Glucose Metabolism: Influence of Time Since Infection and Fatigue Status

Abstract

Post-COVID-19 syndrome (PCS) fatigue is typically most severe <6 months post-infection. Combining magnetic resonance imaging (MRI) and positron emission tomography (PET) imaging with the glucose analog [18F]-Fluorodeoxyglucose (FDG) provides a comprehensive overview of the effects of PCS on regional brain volumes and metabolism, respectively. The primary purpose of this exploratory study was to investigate differences in MRI/PET outcomes between people < 6 months (N = 18, 11 female) and > 6 months (N = 15, 6 female) after COVID-19. The secondary purpose was to assess if any differences in MRI/PET outcomes were associated with fatigue symptoms. Subjects > 6 months showed smaller volumes in the putamen, pallidum, and thalamus compared to subjects < 6 months. In subjects > 6 months, fatigued subjects had smaller volumes in frontal areas compared to non-fatigued subjects. Moreover, worse fatigue was associated with smaller volumes in several frontal areas in subjects > 6 months. The results revealed no brain metabolism differences between subjects > 6 and < 6 months. However, both groups exhibited both regional hypo- and hypermetabolism compared to a normative database. These results suggest that PCS may alter regional brain volumes but not metabolism in people > 6 months, particularly those experiencing fatigue symptoms.

Decoding Post-Viral Fatigue: The Basal Ganglia’s Complex Role in Long-COVID

“…However, both groups showed hypo-and hypermetabolism in certain regions compared to a healthy normative database. The results suggest that mild COVID-19 may lead to delayed decreases in subcortical and frontal lobe volumes, particularly in those with persistent fatigue (Figure 2; [23]). The mechanisms are unclear but could involve basal ganglia-cortical circuits underlying motivation and motor control.…”

“…Lastly, Deters et al [23] explored brain volume and glucose metabolism changes in 33 people with prior mild COVID-19, divided into a <6-month post-infection group (n = 18) and a >6-month post-infection group (n = 15). The >6-month group showed smaller volumes in the putamen, pallidum, and thalamus compared to the <6-month group.…”