Previous COVID Infection Linked to Cognitive Impairment, Lower Brain Oxygen Levels: Study

A new study has revealed that previous COVID infection can cause lower brain oxygen levels and cognitive problems. The study was published in January and found that during a task measuring executive function, those with a history of COVID-19 performed significantly worse.

The Canadian study titled ‘Neurocognitive and psychiatric symptoms following infection with COVID-19’ was published in January in the peer-reviewed journal Brain, Behaviour & Immunity. It used data from a national population survey of Canadians in 2021 and 2022, and a lab study involving cognitive tests while having their brains imaged.

In the lab study, 120 participants from 18-84 years old performed three cognitive tests, one measuring executive function, another looking at impulsive decision-making, and the third looking at reaction time. The study found that reaction time was not affected by prior COVID infection. However, executive function and impulsive decision-making were negatively impacted.

Those with a history of COVID-19 performed significantly worse on the test. Brain imaging showed that there was a clear lack of oxygen saturation in a region of the brain specific to that task.

The second part of the study involved a survey of 2,000 Canadians between the ages of 18 to 56 years old. Those who had a history of COVID-19 reported problems with concentrating and inhibition, as well as higher levels of depression and anxiety.

Dr. Peter Hall, the lead author of the study said, “It appears that, regardless of gender and other demographic factors, COVID-19 infection at baseline is correlated with increased problems with emotion regulation six months later: depression, anxiety and agitation. In some cases, we are talking about symptom levels that are at or above recommended as cut-off scores for psychiatric diagnoses.”

It was also noted that older women experienced less oxygen saturation during the cognitive tests compared to other groups that had previous cases of COVID-19. Hall added, “We don’t know for sure why this was the case, but there have been other studies showing that older women are especially impacted by some post-COVID-19 syndrome symptoms.”

Talking about the two studies, Dr. Hall said that these studies highlight that the full range of the negative effects of COVID-19 need to be understood. He added that they still need to find out how vaccinations affect the course of long COVID, among other aspects.

Vineet Washington