long covid brain is biologically similar to cognitive impairment caused by cancer chemotherapy, and doctors often refer to it as "chemo brain." In both cases, excessive inflammation damages the same brain cells and processes.
Even mild COVID can cause significant inflammation in the brain, which can dysregulate brain cells and can lead to cognitive impairment, an overlap between the cognitive consequences of COVID-19 and what happens in chemotherapy brains, as people As is well known, it could be good news for patients, as it could speed up research into treatments.
The exciting news is that, because the pathophysiology is so similar, research related to cancer treatment over the past few decades could guide us to treatments that might help with COVID brain fog.
Damaged nerve insulation
Monje's team has spent two decades studying cognitive impairment after cancer. They revealed key details of how chemotherapy impairs the function of the brain's white matter, an area of the brain normally rich in well-insulated nerve fibers that quickly transmit signals from one place to another. Myelin is the fatty coating that insulates the long arms of neurons and helps speed up the transmission of nerve signals. In chemotherapy brains, damage to myelin slows their transmission.
When the pandemic started, I became concerned that we would see similar neurological consequences of this highly immunogenic virus, and because the virus elicited such a strong immune response, including widespread inflammation, she suspected it might also contribute to cognition question.
Many COVID-19 survivors experience cognitive impairment. Cognitive symptoms persist for at least two months in about a quarter of COVID-19 patients, even after mild infection. Symptoms in patients include impaired concentration, focus, memory, and executive function, as well as slower information processing. All of these are also common in people who have had chemotherapy brains after cancer treatment.
Monje and her colleagues examined brain changes in mice in which the researchers had induced SARS-CoV-2 infection confined to the respiratory system. Mice lack the cellular receptors that the SARS-CoV-2 virus uses to invade human cells, but the animals in the study were genetically engineered to express the necessary receptors in the airways. After exposure to SARS-CoV-2, the mice were mildly infected: they did not lose weight or behave as if they were sick, and no virus was found in their brains.
How Long Will Symptoms Of Brain Fog Last After Being Infected With Covid-19? refers to a 2022 study investigating recovery in individuals with long-term COVID and neurological symptoms such as brain fog. The average duration of brain fog was 14.8 months since participants developed symptoms of COVID-19 infection. After the initial assessment, participants were followed for 6 to 9 months. During the follow-up period, reports of brain fog symptoms did not change significantly compared to the initial assessment, meaning that most brain fog patients did not change significantly. Quality of life indicators for study participants remained lower than for the general population, the researchers noted.
According to published medical statistics papers on long COVID brain fog, symptoms can persist for quite a long time. Symptoms of brain fog tend to peak within a few months of contracting COVID-19 and usually improve over time. Recent research has found that symptoms of brain fog can persist for more than a year after contracting COVID-19. Additionally, studies have shown that more than 20% of people with chronic long covid brain damage experience no improvement in symptoms after one year.