The brain inflammation and impaired "brain circuitry" seen in people who die of COVID-19 look a lot like what doctors see in the brains of people who die of neurodegenerative conditions such as Alzheimer's disease and Parkinson's disease, researchers reported on Monday in the journal Nature.
Analysis of brain tissue from eight people who died from COVID-19 and 14 others who died from other causes showed "striking changes" in the COVID-19 patients' brains, Stanford University researcher Tony Wyss-Coray told Reuters. His team at Stanford, with colleagues at the University of Saarbruecken in Germany, analyzed thousands of genes in each of 65,309 individual cells taken from the brain-tissue samples. Genes involved with cognition, schizophrenia and depression were more often "turned on" in the COVID-19 patients' brains, they found. "There also were signs of distress in neurons in the cerebral cortex, the brain region that plays a key role in decision-making, memory and mathematical reasoning," the researchers said in a statement. "These neurons ... form complex logic circuits that perform those higher brain functions."
Wyss-Coray said his team could not find the virus itself in the brain, which suggests that "virus infection in the rest of the body could be enough to cause neurological symptoms, even in people who do not die from the disease." The findings, Wyss-Coray noted in a statement, "may help explain the brain fog, fatigue and other neurological and psychiatric symptoms of long COVID."
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