Long COVID promotes brain network integration and reduces segregation during the acute phase

Motivation: Long COVID is characterized by debilitating fatigue, likely arising from abnormalities in interactions among brain regions. However, it is unclear whether such abnormalities can emerge in the early stage of long COVID. Goal(s): To link the brain functional organizations with long COVID symptoms, we measured functional segregation and integration in brain networks. Approach: We employed the nested-spectral partition method to analyze network integration and segregation. Results: During the acute phase of COVID-19, long COVID patients exhibited significantly higher fatigue scores than healthy controls, with their brain networks showing more integration and less segregation. Positive correlations between network integration and fatigue symptoms were found. Impact: Unlike the typical cross-sectional studies conducted six months or more after COVID-19 infection, our study offers a unique opportunity to understand the early neural mechanisms of long COVID and their association with fatigue symptoms.