Brain fog can linger after COVID
NEW HAVEN — As the COVID-19 pandemic enters its second year, neurologists are finding that patients frequently suffer difficulties in concentration and memory, even after recovering from the acute illness.
In some cases, chemicals formed to fight the coronavirus are causing bleeding in the brain and even strokes, though the instances of these are rare.
Dr. Serena Spudich, a neurologist with the Yale School of Medicine, is one of a team operating a neuroCOVID clinic, which has been see patients via telehealth visits. The clinic began seeing patients monthly, but now is run four times a month. There have been about 30 patients seen so far, Spudich said.
As the pandemic has progressed, “we started to realize that there seemed to be some impact in the nervous system and that was something that other clinicians, other investigators in Asia and Italy and the United Kingdom were seeing,” Spudich said.
The neurological issues patients were having after the major COVID symptoms had gone were so frequent that a specialized clinic was created within the Yale Medicine practice, including Dr. Shelli Farhadian and Dr. Lindsay McAlpine.
“We wanted to get prepared because we realized there would be a variety of conditions that patients would be coming in with,” Spudich said.
“Headache has been one of the most common” complaints, some of them persistent or severe enough to interfere with daily living, Spudich said. Other issues contribute to “brain fog.”
“The primary concern is the sense that they are having trouble with concentration, memory and daily functioning in their lives,” Spudich said.
Patients reported that they could not focus on their work or studies or had difficulty falling asleep or waking up.
“Many of these issues are fairly subtle for the patients, so they may be able to function on a daily basis,” she said. But the range of neurological symptoms has been broad, including a burning sensation on the skin, weakness and visual changes.
“It’s not the majority that they’re so debilitated that they can’t work,” Spudich said. Perhaps a fifth suffer that severely.
For most, “it’s really remarkable what people continue to work through,” she said.
Besides physical symptoms, “there’s also a significant mental health issue that some patients are exhibiting,” including depression, anxiety and post-traumatic stress disorder,” Spudich said. “There’s always been a link that’s been presumed between brain inflammation and some mental health and mood disorders.”
Dr. Arman FesharakiZadeh, a behavioral neurologist and neuropsychiatrist, is part of the clinic’s team.
It’s not necessarily the coronavirus that causes neurological problems. Often it’s the body’s attempt to fight off the infection, the doctors noted.
“One major issue with COVID is it causes a lot of inflammation in the body,” Spudich said. That triggers the body’s immune system, which releases cytokines, proteins such as interferon and interleukin.
While not necessarily a “cytokine storm” that overwhelms the body, the response still can cause problems when the chemicals pass through inflamed blood vessels into the brain.
“It doesn’t seem that the virus, SARS-CoV-2, which causes COVID, is robustly affecting the brain, which is good, but even though maybe the virus itself isn’t attacking the brain … the immune response seems to be causing these problems,” Spudich said.
“Many of these patients we’re seeing were never severely ill. They were never severely ill in the ICU,” Spudich said, but the cytokines released by immune cells are enough to cause lingering after effects.
“It may be that addressing immune issues would address all the underlying issues that we’re seeing,” she said. “There’s so much we don’t know. This is all the best hazard of a guess. What we’re doing basically is trying to listen to each patient’s story, how sick were they, what kind of lab values did they have, how long were they sick, what they were treated with.”
In some cases, COVID may have exacerbated neurological problems the patient had before; in other cases they could be new symptoms.
While the neuro-COVID clinic treats patients, Dr. Amit Mahajan, assistant professor of radiology and biomedical imaging at Yale School of Medicine, has been researching the effects of the disease on the brain, using CT scans and MRIs. He is corresponding author of a study in the American Journal of Radiology of patients in the New York metropolitan area at the beginning of the pandemic.