Severe COVID-19 may result in premature aging in recovered patients
Over the past two years, researchers are uncovering how COVID-19 impacts various organ systems. One organ affected by COVID-19 is the brain, with severe patients displaying neuropsychiatric problems. Recently, researchers have found that severe COVID-19 infection may result in premature brain aging in recovered patients. In this blog post, we discuss how severe COVID-19 may result in premature aging in recovered patients.
What is processing speed?
Processing speed is a cognitive function that represents the time it takes for someone to understand information and use it to complete a task. We use processing speed when we listen to a lecture, take notes in class, read graphs in a work meeting to make business decisions, and hold conversations with friends and family. People often think of processing speed as a measure of intelligence, but that is not the case. People can be highly intelligent but have difficulty processing speed due to various medical conditions.
Can severe COVID-19 infection result in premature brain aging in recovered patients?
Previous research suggests that severe infection may damage the frontal cortex of the brain, which is responsible for executive functioning. When people age, frontal cortex functions naturally decrease with reduced synaptic activity. COVID-19 appears to cause a similar decrease in brain signaling as aging does, but it is not clearly understood. To better understand the impacts of COVID-19 on the brain, researchers conducted a study to investigate if severe infection resulted in decreased brain signaling, similar to aging.
Researchers examined postmortem frontal cortex tissue of 12 people who had COVID-19 compared with 12 people who were not infected. Researchers used quantitative polymerase chain reaction (qPCR) to show the absence of SARS-CoV-2 in the brain tissue. Using clustering analysis (t-SNE), researchers found that the biological profiles of COVID-19 patients were distinct from those of those who had not been infected. qPCR analysis revealed that SARS-CoV-2 was absent in the frontal cortex of both COVID-19 patients and controls at the time of death, which indicates that gene expression changes observed in COVID-19 patients were not a direct result of the impact of the virus on the frontal cortex.
Analyses revealed differences in gene expression within the frontal cortex tissue of COVID-19 patients versus controls. In addition to observed gene expression differences between people who had COVID-19 and those who did not, researchers examined the effect of age on COVID-19 gene expression differences. Researchers found that in people under 65 years old who passed away from COVID-19, age-related gene signatures were more pronounced than older adults who passed from COVID-19. This means that younger people’s brains display more age-like changes in gene expression than do older adults who have had COVID-19.
While this study is small, it is the first one to demonstrate that COVID-19 infections result in molecular changes within the brain tissue. These changes may explain increased cognitive impairment and neurodegeneration in survivors of COVID-19. Clinical providers may want to monitor people who have recovered from COVID-19 for aging related cognitive problems.