The Hindu reported that lost connections between nerve cells in the brain may help explain symptoms of long COVID. For some who are infected by COVID-19 symptoms can persist for months and even years after the initial infection. Even people with mild symptoms during the initial infection can get long COVID symptoms.
Some experience “Brain Fog” which affects memory, concentration, sleep and speech. There is also concern that those infected can develop brain disorders, such as dementia years after getting infected.
Stem cell research is helping researchers discover how long COVID may be developing. By infecting these cells called organoids, researchers found that an excessive number of synapses (the connections between brain cells) were eliminated – more than you would expect to see in a normal brain. Synapses are important because they allow neurons to communicate with each other. The elimination of these connections could explain why some experience cognitive symptoms as part of long COVID.
This excessive pruning process is similar to other neurodevelopmental disorders such as schizophrenia, as well as neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease. One limitation of the study is that the cells tested are more similar to a fetal brain rather than an adult brain. It can not be postulated therefor that these effects are the same in an adult brain.
COVID is an RNA virus. Similar lost connections have been seen in mice infected with other RNA viruses that can also cause residual cognitive symptoms, such as the West Nile virus.
Research needs to be done to see if any drugs can inhibit the changes caused in the brain after infection with COVID-19.