(NEXSTAR) – Whether you were hospitalized with COVID-19 or only briefly slowed down by a mild case, the virus is may have altered your brain tissueaccording to a new study.
Researchers led by a team from the University of Oxford compared brain scans of people who had received COVID-19 with those who did not, and found marked differences, according to the study, which was published Monday in the journal Nature.
Of the 785 British participants aged 51 to 81, just over half got the virus, and most cases came when the alpha variant was widespread. The pictures came from UK Biobank databasewhich dates back to 2014, thus providing ideal pre-pandemic “before” scans.
“Using the UK biobank resource, we were in a unique position to look at changes that took place in the brain after mild – as opposed to more moderate or severe – SARS-CoV-2 infection,” said the study’s lead author, Gwenaëlle Douaud, professor in the Department of Clinical Neuroscience at the University of Oxford. “Despite the fact that the infection was mild for 96 percent of our participants, we saw a greater loss of gray matter volume and greater tissue damage in the infected participants on average 4.5 months after infection.”
The researchers compared subjects with matching characteristics when it came to age, gender, baseline test date, and health issues when evaluating scans.
Most changes in the brain were found in areas bound to the sense of smell, according to Douaud. All the adverse effects were pronounced in older people.
The study showed that people who had COVID-19 also showed a general reduction in brain volume and performed worse during cognitive follow-up tests.
Data suggested that the tissue damage found in the 15 people admitted with COVID was worse than in the people who experienced mild cases, but Douaud said the sample size was too small to be decisive.
What causes the brain changes is not yet known, the researchers said, but some of the working theories include COVID-related inflammation in the tissue and a form of “sensory deprivation” that may be caused by the virus’ effect on the sense of smell.
“A key issue for future brain imaging studies is to see if this brain tissue damage disappears in the long run,” said Douaud.