Preliminary research: Even mild COVID can shrink the brain

Early on in the pandemic, one of the most common reports from those infected with COVID-19 was the loss of sense of taste and smell.

Strikingly, the brain regions that the U.K. researchers found to be impacted by COVID-19 are all linked to the olfactory bulb, a structure near the front of the brain that passes signals about smells from the nose to other brain regions. The olfactory bulb has connections to regions of the temporal lobe. We often talk about the temporal lobe in the context of aging and Alzheimer’s disease because it is where the hippocampus is located. The hippocampus is likely to play a key role in aging, given its involvement in memory and cognitive processes.

The sense of smell is also important to Alzheimer’s research, as some data has suggested that those at risk for the disease have a reduced sense of smell. While it is far too early to draw any conclusions about the long-term impacts of these COVID-related changes, investigating possible connections between COVID-19-related brain changes and memory is of great interest — particularly given the regions implicated and their importance in memory and Alzheimer’s disease.