When brain cells come in contact with blood taken from COVID-19 patients with confusion (delirium), there is an increase in the number of dead cells and a decrease in the rate of new brain cell formation, a study by scientists at King's College London has found.
Delirium is a state of confusion, indicating that in these patients, the COVID-19 infection has affected the brain, Molecular Psychiatry reported.
The cause of the development of neurological symptoms in patients with COVID-19 is an overactive immune response called the cytokine storm. Cytokines produced by immune cells in response to infection can travel from the blood to the brain and directly affect neurological processes.
The study collected serum samples from 36 patients who became ill during the first wave of the COVID-19 pandemic in the United Kingdom (March-June 2020). Half of the patients experienced symptoms of delirium. Scientists treated hippocampal cell cultures with serum samples and observed the effects on cell formation and death.
Serum taken from COVID-19 patients with delirium increased cell death and decreased the formation of new brain cells. The results also showed that patients with delirium had higher levels of the cytokine IL6, and the levels of two other cytokines, IL12 and IL13, were elevated in response to treatment of brain cells with serum in neuronal culture, suggesting a biochemical cascade in which IL12 and I1L3 are generated by brain cells in response to IL6-induced inflammation in the body. All of these together can cause delirium.