MRI data suggest COVID likely affects the neurological health of everyone, even those who fully recover
Even if an individual has fully recovered from COVID-19 and is able to return to their normal daily activities, the structural and chemical makeup of their brain may not return to its pre-COVID state.
This phenomenon is even more pronounced among individuals affected by long COVID, according to new findings published in Brain, Behavior, and Immunity - Health. The study’s results suggest that both individuals who believe they have fully recovered from COVID and those who continue to struggle with long-term symptoms show changes in their brains' tissue microstructure and neurochemical levels.
Much of the research on COVID over the last couple of years has focused on those who struggle with lingering fatigue, respiratory symptoms, brain fog and cognitive function (among other symptoms). However, some smaller studies have indicated the same neural mechanisms that underlie long COVID may also be present in COVID-recovered individuals.
This latest study built on that data by using MRI to analyze changes in myelin and neurochemical levels of the brain.
“Importantly, cognitive impairments are not limited to those with ongoing systemic symptoms; they are also evident in COVID-19 recovered individuals who no longer report active symptoms, compared to healthy controls without SARS-CoV-2 infection,” Kiran Thapaliya, with the National Center for Neuroimmunology and Emerging Diseases in Australia, and colleagues noted. “Studies of [COVID-19 recovered individuals] have identified deficits in key cognitive domains, including processing speed, executive function, memory encoding and recall, with effects observed up to seven months post-infection. Collectively, these findings suggest central nervous system involvement in both post-acute and long-term phases of SARS-CoV-2 infection, with measurable effects on cognitive functioning.”
The team recruited 47 individuals—one group with known long COVID, one that had recovered from the virus and another with no known history of the disease—to undergo 3T MRI scans. T1 and T2 weighted images were acquired to assess myelin signal, while diffusion weighted images were used to analyze tissue microstructure, and magnetic resonance spectroscopy data were compiled to estimate brain neurochemical levels.
The imaging findings differed significantly between each group. The team observed altered T1w/T2w signal between long COVID versus the COVID-recovered group, long COVID versus healthy controls, and the COVID-recovered cohort compared to healthy controls. What’s more, the signal intensity showed significant associations between participants’ cognitive and physical function. The diffusion weighted images revealed altered tissue microstructure that differed between each group, while the long COVID and COVID-recovered group showed the greatest variation in neurochemical levels.
“These novel findings suggest that COVID-19 may lead to lasting brain alterations that potentially impact overall brain function even after recovery,” the group cautioned.
Their findings do not provide new information on whether these changes are permanent, the authors added, with more long-term follow-up studies needed to determine how these findings might change over time.
For more detailed information on the findings, click here.
In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.