Neuroimaging data suggests that even mild COVID-19 affects brain matter and functioning

By Shelly Seth. This article was initially published in our Concussion Update newsletter; please consider subscribing.

An article from PsyPost highlights a UK study that looked at patients’ brain scans before and after they contracted the SARS COVID-19 Virus. This study was conducted in August 2021, when more was known about the virus, its common symptoms, and variations in recovery processes among patients. 

This preliminary study, available on MedRxiv, used data from UK Biobank, a database containing brain imaging results from over 45,000 patients since 2014. Researchers used these initial brain scans as a baseline and contacted patients who had since contracted COVID-19 to scan their brains again and look for changes. They compared patients who had contracted with COVID-19 to patients who had not been infected and controlled for “age, sex, baseline test date, and study location, as well as common risk factors for disease, such as health variables and socioeconomic status.”

Most notably, the researchers found decreased gray matter thickness in the frontal and temporal brain lobes of those who’d had COVID-19 compared to those who had not had the virus. The researchers also found that, based on “performance on cognitive tasks,” those who had contracted COVID-19 were slower in processing information (the primary function of gray matter in the brain). The researchers note that although gray matter decline is standard over time, the observed decreases were more extensive than expected in the COVID-19 group. 

Additionally, they found that even milder cases of COVID-19 that did not require hospitalization showed similar gray matter reductions to more severe cases of COVID-19 requiring hospitalizations. The researchers acknowledge limitations in this study, mainly that it is a preliminary study and is awaiting peer review. They also note the difficulty in drawing conclusions about cognitive performance from initial findings.