These range in severity and presentation. And now new research from Imperial College London suggests that the novel coronavirus can cause chronic cognitive deficits in critically ill patients–even after recovery.
It should be noted that the new paper has yet to be peer-reviewed. Similarly, the mental capacity of the 84,285 patients studied was not determined before analysis. The effects indexed below offer compelling insights into COVID-19’s pathology but should not be assumed to be typical or permanent.
Having said that, cognitive decline evidenced among the patient sample was severe enough to disrupt daily functions. Moreover, the worst cases exhibited impaired brain function “equivalent to the average 10-year decline in global performance between the ages of 20 to 70”.
Cognitive performance was measured with similar tests designed to detect dementia.
“Case studies have revealed neurological problems in severely affected COVID-19 patients. However, there is little information regarding the nature and broader prevalence of cognitive problems postinfection or across the full spread of severity,” the authors wrote of their findings in the new paper published in Medrxiv. “People who had recovered, including those no longer reporting symptoms, exhibited significant cognitive deficits when controlling for age, gender, education level, income, racial-ethnic group, and pre-existing medical disorders. They were of substantial effect size for people who had been hospitalized, but also for mild but biologically confirmed cases who reported no breathing difficulty. Finer grained analyses of performance support the hypothesis that COVID-19 has a multi-system impact on human cognition.”
The strength of these observations is two-fold. Premilnary research like this most recent addition reminds us that we have to appreciate COVID-19 data sets soberly. These studies aren’t really for our immediate benefit, but for the benefit of clinicians and vaccinologists toward the development of countermeasures.
The odds of you personally suffering provisional cognitive impairment after recovering from COVID-19 may be very low, but health systems need to devise a course of action for the growing community that does.
The link between neurological effects and the novel coronavirus has long since been established, which warrants further investigation.
“The results align with the ‘brain fog’ reported by many people who, even months after recovery, say they are unable to concentrate on work or focus how they did before,” Dr.Adam Hampshire, who led the new study, explained in a media release.
The other strength of this study concerns the seriousness of COVID-19. In some ways, alerting the public to the worst the disease has to offer (however infrequently the worst presents itself) encourages the majority of people who will recover without medical intervention take precautions to protect those who will not.
So far, case severity is still somewhat of a mystery, This is doubly true with respect to cognitive decline.
“As researchers seek to better understand the long term impact of COVID, it will be important to further investigate the extent to which cognition is impacted in the weeks and months after the infection, and whether permanent damage to brain function results in some people,” Derek Hill, a professor of medical imaging science at University College London, said in a statement.