COVID-19 Virus Directly Impairs Brain Function, Causing Memory Loss

A new study has found that the COVID-19 virus directly affects brain function, reducing concentration and memory.

Korea Disease Control and Prevention Agency's National Institute of Health announced on Thursday that it has scientifically identified the cause of cognitive impairment, including reduced concentration and memory, reported after COVID-19 infection through animal experiments.

In the experiments, when the spike protein (S1) of the COVID-19 virus was administered to the noses of mice, learning and memory abilities decreased, as evidenced by longer times needed to find hidden platforms. Additionally, increased anxiety behavior in unfamiliar spaces was observed, showing patterns similar to cognitive decline that appears after COVID-19 infection.

This is attributed to the S1 protein reaching the brain and interfering with connections between nerve cells (synapses), while also reducing the expression of NMDA receptor genes that play a crucial role in memory formation.

Furthermore, six weeks after S1 protein administration, a reduction in the number of nerve cells was observed in the mice's brains (hippocampus).

The study also confirmed increased accumulation of toxic proteins "tau" and "alpha-synuclein," which are known to cause degenerative brain diseases such as dementia and Parkinson's disease, raising concerns about potential long-term brain damage.

However, researchers observed that when the diabetes medication metformin was administered under the same conditions, nerve cell function recovered and toxic protein accumulation decreased.

Metformin is a widely used diabetes treatment.

"This study is significant in that it reveals the pathological mechanism of cognitive impairment that appears after COVID-19 infection and suggests the possibility that metformin, which is widely used clinically, can suppress it," said the research team led by Dr. Ko Young-ho at the National Institute of Health. "Clinical studies are needed to examine its potential as a treatment for long COVID symptoms such as reduced concentration and memory."

KDCA Commissioner Lim Seung-kwan said, "Research is needed for patients who experience prolonged symptoms even after COVID-19," adding, "We will continue to support research to establish evidence-based infectious disease policies."