Researchers at the Baylor College of Medicine reviewed 84 studies involving more than 600 patients who had been diagnosed with COVID-19. The median age was 61, and two-thirds of the patients were men, while one-third were women. The study’s authors examined the results of patients’ electroencephalograms — known as EEGs, the tests detect abnormalities in brain waves, according to Johns Hopkins Medicine — and found that brain abnormalities in COVID-19 patients were “common.”
“Diffuse slowing of the brainwaves was the most common finding, which suggests that the brain is not working as good as it usually does,” Dr. Zulfi Haneef, co-author of the study and an assistant professor of neurology and neurophysiology at Baylor College of Medicine, tells Yahoo Life.
In addition, “older males seem more susceptible to brainwave changes,” says Haneef. This dovetails with recent research that reveals the virus is more deadly in older populations and in men.
The most common reason doctors in the studies ordered EEGs was for COVID-19 patients with “altered mental capacity,” explains Haneef, such as not being “fully conscious, not answering appropriately, or general slowness” of mental activity, followed by seizure-like events.
Assad Amin, MBBS, an assistant professor of neurology in the epilepsy division at the Ohio State University Wexner Medical Center, tells Yahoo Life that the “majority of the patients’ EEG findings [in the study] were consistent with what we typically see in critically ill patients with encephalopathy and results in altered mental status.”
This isn’t the first study to look at how COVID-19 affects the brain. In a previous study, published in the journal Brain, Behavior, and Immunity in July 2020, MRIs revealed “white matter [brain] abnormalities” such as “small bleeds and strokes” in COVID-19 patients.
Dr. Lawrence Steinman, professor of neurology and neurological sciences, pediatrics, and genetics at Stanford University School of Medicine, tells Yahoo Life that “in COVID-19 infection, the clotting cascade is activated, making the brain and other organs susceptible to these small strokes. The small strokes can be associated with brain damage and even seizures.”
COVID-19 and the brain
Some of the brain abnormalities related to a COVID-19 infection are brought on indirectly — the result of other organ systems being affected by the virus, such as “lung involvement causing less oxygen to reach the brain, and heart involvement causing less blood to reach the brain,” Haneef explains.
But Haneef and the study’s co-author, Arun Antony, MD, a faculty member in the University of Pittsburgh School of Medicine’s Department of Neurology, are “particularly interested” in whether the virus directly involves the brain after finding that the most common brain changes were seen in the frontal lobe — which is located right behind the forehead and plays a key role in awareness, memory, attention and speech.
“While we don’t have direct evidence for that in our study, there is some suggestion that the predominance of frontal lobe changes — which is near the nasopharynx/nose entry point of the virus — indicates direct viral spread,” he says.
Steinman, who calls this latest research “a well-conducted study scanning a large body of literature,” agrees with Haneef, saying that “the EEG activity in the frontal lobe may be an early sign that one of the portals of entry is via the olfactory nerve. The nose is rich in the ACE2 receptor that binds with the spike protein on SARS-CoV2 [the virus that causes COVID-19], and a presumed pathway to the front of the brain is via the olfactory nerves.”
Are the brain abnormalities permanent?
It’s also not yet clear whether some of these COVID-19-related brain changes are temporary. “We do not know that for sure,” says Haneef, “but given that there are several reports of brain MRI abnormalities, it is very likely that many of these are permanent.”
Haneef adds that, in his study, they saw seizures in more than 5 percent of COVID-19 patients, which “indicates some level of brain damage.” He says, “Any brain damage is likely permanent as the brain is not a tissue that can regenerate itself.”
Steinman adds that “our understanding [of COVID-19 brain abnormalities] is a work in progress,” and that “hopefully” any neurological changes patients experience will “wane with time.” However, Steinman adds, “I think that the damage caused by the small strokes may have some permanence.”
Haneef says this research underscores the seriousness of the virus and its long-term consequences. “A lot of people think they will get the illness, get well, and everything will go back to normal,” Haneef stated in a Baylor College of Medicine press release. “But these findings tell us that there might be long-term issues, which is something we have suspected and now we are finding more evidence to back that up.”
In the meantime, Amin says this latest study “emphasizes the role that EEG may play in diagnosing neurological manifestations of COVID — in this case, seizures — and perhaps future complications.”
For the latest coronavirus news and updates, follow along at https://news.yahoo.com/coronavirus. According to experts, people over 60 and those who are immunocompromised continue to be the most at risk. If you have questions, please reference the CDC’s and WHO’s resource guides.
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