New research suggests that long Covid and Alzheimer’s disease may share underlying biological processes, raising new questions about the long-term effects of SARS-CoV-2 on brain health.
The study, led by researchers at New York University, analysed brain imaging and biomarker patterns in individuals with long Covid symptoms. Participants with persistent neurological symptoms exhibited an approximately 10 per cent enlargement of the choroid plexus — a network of blood vessels involved in producing cerebrospinal fluid and regulating immune responses in the brain — compared with people who had recovered fully or never had Covid-19.
Enlarged choroid plexus structures have been previously linked to impaired waste clearance and chronic inflammation, mechanisms associated with dementia and Alzheimer’s disease.
The research also found that changes in blood proteins tied to Alzheimer’s, as well as slightly lower performance on cognitive screening tests, were more common among those with larger choroid plexus volumes.
Structural changes observed included increased volume and reduced blood flow through choroid plexus vessels, which may hinder cerebrospinal fluid production and its role in removing metabolic waste from the brain. Scientists say the findings point to possible shared pathways between long Covid and neurodegenerative disease processes, though the exact significance of these changes for long-term cognitive outcomes remains to be determined.
Further longitudinal research will be needed to clarify whether such brain alterations precede cognitive decline or are a consequence of sustained immune responses following Covid-19 infection.
