A new study from Griffith University in Australia has identified lasting brain changes in individuals who have had COVID-19, including those who report full recovery. The research utilized advanced multimodal MRI techniques to map these alterations, described as distinct fingerprints on the brain’s microstructure and chemical balance. The study found that individuals who had recovered from COVID-19 (COVID-RHC) exhibited altered tissue microstructure in key brain regions such as the brainstem, cerebellum, and superior longitudinal fasciculus. The brainstem is involved in vital functions like sleep and respiration, while the cerebellum manages coordination. These findings suggest that the virus may leave a neurological footprint even after seemingly mild infections. Dr. Kiran Thapaliya, lead author of the study, stated that the multimodal MRI approach revealed significant alterations in brain neurochemicals, brain signal intensity, and tissue structure across all participant groups, which included Long COVID patients, recovered individuals, and healthy controls. The research also indicated an association between altered brain tissue and symptom severity in Long COVID patients, suggesting a potential silent, lasting effect on brain health. Further insights emerged regarding myelin, the protective sheath around neurons. In Long COVID patients, scans showed increased signal intensity in myelin mapping within the precentral gyrus (involved in motor control) and middle temporal gyrus (linked to memory and cognition). While previous post-mortem studies indicated myelin loss in severe COVID cases, this current study on living patients suggests a process of remyelination. This indicates the body's attempt to heal following viral damage. The persistence of these processes in both Long COVID and recovered patients suggests that COVID-19's impact extends beyond a simple respiratory illness, affecting the central nervous system long-term. The findings were published in the journal Brain, Behavior, and Immunity – Health.