Changes in brain function, and abnormal brain activity during memory tests on functional magnetic resonance imaging (MRI) in people who continue to experience brain fog, memory problems, or other neuropsychiatric symptoms months after receiving a COVID-19 diagnosis.
This was the result found by a study made by researchers from the University of Maryland School of Medicine (UMSOM).
Long COVID combined with neurological symptoms was related to decreased activity in some brain regions utilized for memory functions and increased activity in other regions. The results were published today in the medical journal Neurology, which is published by the American Academy of Neurology.
“The greater activity occurred outside of the normal working memory brain network. We often see such changes in patients with a brain injury: Deficits in the default mode network of the brain leads to an increase in activity in other regions to help maintain brain function,” said study leader Linda Chang, MD, MS, Professor of Diagnostic Radiology and Nuclear Medicine, and an associate member of the Institute of Human Virology (IHV), at the University of Maryland School of Medicine.
“While our study doesn’t prove that COVID caused these brain changes, there appears to be a strong association with these changes and lingering neuropsychiatric symptoms.” she added.
An estimated 30 percent of those who had COVID-19 infections develop chronic symptoms known as long COVID. More than half of these patients develop cognitive or psychiatric symptoms with fatigue, difficulty concentrating, feeling depressed and anxious, being among the most prevalent symptoms, according to a report released in January by the Substance Abuse and Mental Health Services Administration.
While some patients experience a resolution of these issues within a year or two of diagnosis, others still suffer from daily disability more than three years after the onset of the pandemic. Researchers have been racing to conduct studies to learn more about long COVID in these patients in an attempt to develop better treatments.
To conduct the new study, Dr. Chang and her colleagues performed functional MRI scans on 29 patients who had COVID-19 an average of seven months earlier and had at least one ongoing neuropsychiatric symptom like memory loss, depression, or anxiety. Nine of these study participants had COVID-19 infections severe enough to require prior hospitalization. The researchers also conducted brain imaging scans in 21 healthy volunteers who had no history of COVID-19 and were of similar age, health status and vaccination status to those with long COVID.
All the participants had tests for thinking and memory skills, emotional health, motor function, as well as measures for symptoms of depression, anxiety, fatigue, and pain. They also had functional MRI brain scans while they performed tests to evaluate their working memory. The scans showed which areas of the brain were active during the tests.
“Even though the majority of people who had COVID-19 in our study reported ongoing problems with concentration and memory, they had scores on various tests for thinking skills that were similar to those who had no history of COVID-19,” Chang said. “This could be because their brains were compensating for these deficits by using more of other parts of their networks to maintain their performance.”
However, the long COVID group did have poorer scores on tests of dexterity and motor endurance than the non-COVID group. They also reported more negative feelings, such as anger and sadness, and higher levels of stress, and they had lower scores for life satisfaction compared to those who never had COVID. In addition, they had higher scores for depression, anxiety, fatigue and pain than the control group. People in the post-COVID group who had greater changes in their brain activity were more likely to have poorer scores in many of these symptom domains.
These patients could benefit from neurorehabilitation or psychiatric treatments, and the researchers recommend that doctors consider these approaches to help manage this condition.
The study had a few caveats: It was conducted mainly during early part of the pandemic when the Delta variant of the SARS-CoV-2 virus was circulating in the US. Results may not apply to the newer coronavirus variants like Omicron, and it is not known whether these newer variants affect the brain similarly. In addition, since antibody testing was not completed on the people who reported no prior COVID-19, it is possible that they had prior infections or exposure to the virus with no symptoms.
The study was funded by the National Institute of Neurological Disorders and Stroke.
Other UMSOM faculty, staff and students who served as co-authors on this study include: Meghann Ryan, MS, Huajun Lian, MBBS, PhD, Xin Zhang, MS, Eric Cunningham, BS, Justin Wang, Eleanor Wilson, MD, Edward Herskovits, MD, PhD, Shyam Kottilil, MBBS, PhD, Interim IHV Director, and Thomas Ernst, PhD.
“While this study provides crucial information on brain function in those who suffer neuropsychiatric symptoms from long COVID, we now need longitudinal follow-up studies to determine whether or when these abnormal imaging patterns will normalize and whether that correlates to a resolution in symptoms,” said UMSOM Dean, Mark T. Gladwin, MD, who is also Vice President for Medical Affairs, University of Maryland, Baltimore, and the John Z. and Akiko K. Bowers Distinguished Professor.