Long COVID Linked to Brain Changes Mirroring Alzheimer’s, New Study Finds
A concerning new study published February 10, 2026, reveals a potential link between Long COVID and structural changes in the brain that resemble early markers of Alzheimer’s disease and dementia. Researchers at NYU Langone Health discovered that individuals experiencing neurological symptoms from Long COVID exhibit an enlarged brain structure with reduced blood flow, alongside elevated levels of proteins associated with cognitive decline.
The Choroid Plexus: A Key Brain Structure Under Scrutiny
The research centers on the choroid plexus (CP), a critical network of blood vessels responsible for producing cerebrospinal fluid – the protective cushion surrounding the brain. This structure also plays a vital role in regulating the brain’s immune response and clearing waste products. Previous research has indicated that the COVID-19 virus can directly damage the cells lining the blood vessels within the CP.
Long COVID and Brain Volume: A 10% Increase
The study, published in Alzheimer’s & Dementia, compared 179 participants: 86 with neurological Long COVID symptoms, 67 who had fully recovered from an initial SARS-CoV-2 infection, and 26 who had never contracted the virus. Advanced MRI scans revealed that patients reporting Long COVID had a CP that was, on average, 10% larger than those who had fully recovered. This enlargement correlated with increased levels of specific proteins in the blood, including pTau217, a biomarker known to rise as Alzheimer’s disease progresses, and glial fibrillary acidic protein, which indicates brain injury.
Cognitive Impact: A Subtle But Significant Decline
Further analysis showed that patients with larger CPs performed approximately 2% worse on the Mini-Mental State Exam, a standard 30-point test used to assess memory and attention. While seemingly small, this difference suggests a measurable cognitive impact associated with CP size.
“Our work suggests that long-term immune reactions caused in some cases after an initial COVID infection may come with swelling that damages a critical brain barrier in the choroid plexus,” explained a senior study author. “Physical, molecular, and clinical evidence suggests that a larger CP may be an early warning sign of future Alzheimer’s-like cognitive decline.”
Understanding the Mechanisms: Inflammation and Vascular Remodeling
The research team theorizes that the observed changes are driven by inflammation-driven CP “vascular remodeling”. This process involves the thickening of blood vessel walls in response to prolonged immune system activation. This inflammation is accompanied by stromal fibrosis, the buildup of scar-like tissue that further restricts blood flow. Impaired blood flow to the CP may disrupt cerebrospinal fluid production, hinder waste removal, and compromise the integrity of the blood-CSF barrier.
Future Research: Tracking Long-Term Cognitive Outcomes
Researchers plan to follow these patients over time to determine if the identified brain changes can predict the development of long-term cognitive impairment. “A larger, long-term study will be needed to clarify whether these CP alterations are a cause or a consequence of the neurological symptoms,” stated another senior author, “which promises to better focus treatment design efforts.”
The study was supported by grants from the National Institute on Aging (R01AG077422, U24 NS135568, and P30AG066512).
NYU Langone Health, consistently ranked among the nation’s top hospitals, continues to lead research into the long-term effects of COVID-19 and neurological disorders. The findings underscore the need for continued investigation into the complex relationship between viral infections, inflammation, and cognitive health.
