Advanced MRI Detects Choroid Plexus Changes in Long COVID Linked to Alzheimer’s-Related Blood Markers

Advanced brain MRI revealed measurable choroid plexus (CP) abnormalities in patients with Long COVID that tracked with Alzheimer’s-associated blood biomarkers and slightly worse cognitive screening performance, according to a recent NYU Langone Health study published Feb. 10 in Alzheimer’s & Dementia.

The choroid plexus is a vascular structure lined by specialized cells that produce cerebrospinal fluid (CSF) and form the blood–CSF barrier. It also plays a key role in neuroimmune signaling and waste clearance. Prior research suggests SARS-CoV-2 can injure the cells lining CP blood vessels, making the structure a target of interest for neuroimaging studies of post-COVID neurologic symptoms.

In the study, investigators used advanced MRI to quantify CP volume and perfusion patterns in 179 participants, including 86 patients with neurological Long COVID symptoms, 67 individuals who recovered from COVID-19 without persistent symptoms, and 26 participants with no history of COVID-19.

MRI analysis showed that Long COVID patients had a CP that was 10% larger than those who had fully recovered. The imaging findings also suggested reduced blood flow through CP vessels, indicating structural and vascular alterations rather than isolated volumetric change.

Importantly, CP enlargement correlated with higher blood levels of biomarkers linked to neurodegeneration and brain injury. These included pTau217, a marker that rises as Alzheimer’s disease worsens, and glial fibrillary acidic protein (GFAP), which increases with brain injury. Patients with larger CPs also performed an average of 2% worse on the Mini-Mental State Exam, a standard 30-point screening tool.

“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,” said senior author Yulin Ge, MD, professor of radiology at NYU Grossman School of Medicine. “Physical, molecular, and clinical evidence suggests that a larger CP may be an early warning sign of future Alzheimer’s-like cognitive decline.”

The authors propose that inflammation may drive CP “vascular remodeling,” with thickening of vessel-lining layers and scarring that restrict perfusion. Such changes could reduce CSF production, impair waste clearance, and compromise the blood–CSF barrier—mechanisms that would be detectable through imaging before more overt structural brain injury appears.

“Our next step is to follow these patients over time to see if the brain changes we identified can predict who will develop long-term cognitive issues,” said senior author Thomas Wisniewski, MD.