People with long COVID and persistent neuropsychiatric symptoms display abnormal brain activity during memory tests. The corresponding study was published in Neurology.
At least 10% of people who contract COVID-19 are expected to develop long COVID, a collection of over 200 symptoms that ranges from rashes to heart palpitations to fatigue. As neuropsychiatric symptoms are relatively common among those with long COVID, in the present study, researchers investigated whether long COVID is linked to abnormalities in brain activation during working memory tasks.
To do so, they enrolled 29 people with long COVID alongside 21 uninfected controls. All participants completed tests that evaluated their thinking and memory skills, emotional health, movement, and measures for depression, anxiety, fatigue and pain. They also underwent functional MRI brain scans while performing three working memory tasks.
Although 79% and 93% of the long COVID group reported memory and concentration difficulties, the researchers noted that their thinking skills test scores were similar to controls. They noted, however, that their brain activity patterns differed from controls when completing the working memory tasks, indicating that their brains compensated for deficits by reorganizing their neural networks.
The researchers further noted that the long COVID group had poorer scores in dexterity and motor endurance tests than the control group. They also reported more negative feelings, including anger and sadness, more stress, lower life satisfaction, and less meaning and purpose. The long COVID group also scored higher for depression, anxiety, fatigue, and pain.
The researchers note that their findings point towards a correlation and not a causal link. They add that as their study was conducted during the delta variant phase of the COVID-19 pandemic in the US, their results may not reflect newer variants of the virus on the brain. Additionally, the control group was not tested for COVID-19 antibodies prior to the study, meaning they may have experienced asymptomatic infections.