Could COVID Brain Fog be Linked to SARS-CoV-2 Fusing with Brain Cells?

Recent research published in Science Advances revealed a new effect of the SARS-CoV-2 virus on brain cells with potential implications for cognitive deficits such as brain fog. Scientists at the universities of Queensland, Macquarie, and Helsinki demonstrated that the virus can cause brain cells to fuse, resulting in large cell masses known as syncytia. Neuronal signaling was also affected, indicating a potential impact on information processing in the brain. However, the studies were isolated to laboratory settings and further research is necessary to determine what effect, if any, this cell fusion has on humans.

Similar studies suggest that SARS-CoV-2 can induce the fusion of other cell types, such as those in the lungs. These cellular structures could potentially facilitate the transfer of the virus between cells and within an organ. The binding of the virus to ACE2, a common protein on mammalian cells, appears to play a critical role in this process. However, while the syncytia structure in lung cells impacts cell bodies, the structure in brain cells seems to affect dendrites and axons, disrupting signaling between neurons and resulting in cognitive deficits.

Although these findings are specific to COVID-19, they may have implications for other viruses that impact brain function, such as the rabies virus. Further research will help to clarify the extent of these effects and their clinical significance.