Thapaliya et al. (2025)
- Authors: Kiran Thapaliya, Sonya Marshall-Gradisnik, Maira Inderyas, Leighton Barnden
- Institutes: National Centre for Neuroimmunology and Emerging Diseases, Griffith University, Queensland, Australia
- Publisher: Brain, Behavior, & Immunity - Health
- Link: DOI
Summary
This study reveals that SARS-CoV-2 infection can leave a measurable, lasting imprint on the brain’s structure and chemistry, even in individuals who consider themselves fully recovered. By identifying specific markers of altered myelin and tissue microstructure that correlate with symptom severity, the research provides a biological framework for understanding the persistent cognitive and physical challenges associated with Long COVID. These findings highlight the potential for long-term neurological consequences in the wider population post-infection.
What was researched?
The study investigated potential long-term alterations in brain tissue microstructure, myelin signal intensity, and neurochemical levels in individuals with Long COVID compared to those who recovered from COVID-19 and uninfected healthy controls.
Why was it researched?
While many COVID-19 survivors experience lingering neurological symptoms, the underlying biological changes in the brain for both symptomatic patients and those who appear to have recovered are not yet fully understood.
How was it researched?
Researchers used advanced 3T multimodal MRI techniques, including T1w/T2w mapping for myelin, diffusion-weighted imaging (DWI) for microstructure, and magnetic resonance spectroscopy (MRS) for neurochemicals. The cohort included 19 Long COVID patients, 12 recovered individuals without symptoms, and 16 healthy controls who had never been infected.
What has been found?
Significant alterations in brain signal intensity and tissue microstructure were found in both the Long COVID and recovered groups compared to uninfected controls. Changes in the T1w/T2w signal, which relates to myelin integrity, were significantly correlated with physical and cognitive function scores. Notably, unique neurochemical profile differences were identified specifically in the Long COVID group when compared to the recovered-healthy group.
Discussion
The findings suggest that the virus may leave a silent, lasting effect on brain health even in the absence of active symptoms. A limitation of the study is the small sample size, which may affect the generalizability of the neurochemical findings across larger populations.
Conclusion & Future Work
SARS-CoV-2 infection leads to measurable neurological changes that persist beyond the acute phase of the illness, regardless of whether a patient reports ongoing symptoms. Further longitudinal research is required to determine if these brain alterations are permanent or if they resolve over time.