The lasting effects of long COVID rage on.
Over 20 million Americans are believed to have the debilitating post-infection condition, suffering symptoms such as severe fatigue, shortness of breath, chest pain, palpitations, dizziness and muscle pain.
Now, new research from NYU Langone Health might explain why some patients experience incessant “brain fog” and memory issues long after a COVID infection.
The researchers propose that long COVID may trigger changes in the brain that resemble the biological processes seen in diseases like Alzheimer’s.
“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 (CP),” said senior study author Dr. Yulin Ge, a professor in the Department 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 CP is a network of blood vessels in the ventricles of the brain that produces cerebrospinal fluid (CSF) and forms the blood-CSF barrier.
CSF cushions the brain and spinal cord from injury, clears waste and transports essential nutrients.
The NYU Langone researchers followed 86 patients with neurological symptoms of long COVID, 67 people who fully recovered from COVID without lasting symptoms and 26 healthy individuals who had never been infected.
They found that participants with long COVID had a 10% larger CP compared with those who recovered from COVID without long-term symptoms.
Now, it may seem like a larger CP would be good, but it’s a key marker of chronic neuroinflammation and neurodegeneration.
It’s also linked to blood-based biomarkers of Alzheimer’s progression, including phosphorylated tau (pTau217) and glial fibrillary acidic protein (GFAP), which rises after traumatic brain injury and stroke.
Participants with larger CPs performed about 2% worse on a 30-point cognitive test.
Enlarged CPs yielded less blood flow through their vessels, which may compromise CSF production and the brain’s ability to efficiently remove waste.
Research has shown that COVID can damage the CP. Ge said that similar CP changes can be seen in infections such as viral meningitis and HIV.
Ge’s team proposed that long COVID causes chronic inflammation that thickens blood vessels in the CP.
“It is currently unknown whether these changes are reversible. We are actively analyzing their follow-up data to address this question,” Ge told The Post.
The findings were published recently in the journal Alzheimer’s & Dementia.
“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 study author Dr. Thomas Wisniewski, the Gerald J. and Dorothy R. Friedman Professor in the Department of Neurology at NYU Grossman School of Medicine.
“A larger, long-term study will be needed to clarify whether these CP alterations are a cause or a consequence of the neurological symptoms, which promises to better focus treatment design efforts.”
