Fever, cough, shortness of breath are the key signs that come to mind with the novel coronavirus, but a new report from China suggests that a decent number of those who get sick with the disease may experience neurological symptoms as well.
As it is with most things related to COVID-19, we are still in the very early stages of collecting data that fully makes sense of what’s happening in the central nervous system. The new research, which was published Friday in the medical journal JAMA Neurology, was relatively small, and more research needs to be done to really confirm the findings.
The study does, however, provide some useful insight. Considering all of the anecdotes from infected people who said they lost their sense of taste and smell, and now with this paper shedding light on the relatively high incidence of other brain-related symptoms, it’s becoming increasingly clear that the virus can have a significant neurological effect on certain people.
Here’s what we know about the neurological impact of the coronavirus so far:
The most common neurological symptoms include headaches and nerve pain
The paper, which looked at 214 patients who tested positive for COVID-19, the disease caused by the coronavirus, found that infected people frequently experienced neurological effects in addition to and also independent of respiratory symptoms.
Of those in the group, 36% experienced some type of neurological symptom. On the mild end of the spectrum, people commonly experienced the loss of taste and smell. Headache was reported in 13% of the patients, dizziness was observed in about 17%, and muscle inflammation and nerve pain occurred in about 19%. In general, the more severe the infection got, the more frequent and intense the neurological complications (think confusion, seizure and stroke).
Sometimes these symptoms were present in tandem with respiratory symptoms, such as a cough or fever. But in other instances, people experienced the neurological symptoms alone with no signs of respiratory distress.
It’s not surprising that this coronavirus is interacting with the nervous system, according to health experts. Looking back at the coronaviruses SARS and MERS, researchers found that those viruses affected the peripheral nervous system (our muscles and nerves) in addition to the central nervous system (the brain), and caused a handful of life-threatening neurological complications including strokes, seizures, encephalitis and meningitis. It’s also not unheard of to see neurological complications, from headaches and trouble concentrating to strokes and seizures, in people with other respiratory illnesses like the flu or pneumonia. It’s not far off to assume that could happen with COVID-19, too.
There are a few theories why this happens
There are a couple of reasons COVID-19 may be causing neurological problems, according to health experts who spoke with HuffPost.
The first is that people may be experiencing a primary infection, which basically means the virus is infecting the very back of the nose (the nasopharynx) and making its way up to the brain. The two aren’t that far apart, after all, so it’s not that long of a journey, said Igor Koralnik, chief of neuroinfectious diseases and global neurology at Northwestern University’s Feinberg School of Medicine.
The virus can spread throughout the body either through the blood or by something called “neuronal spread,” in which brain cells talk to one another, according to Rohan Arora, director of the stroke program at Northwell Health’s Long Island Jewish Forest Hills hospital in Queens, New York.
The virus then latches onto a receptor in our bodies called ACE-2, which is primarily located in the lungs (hence the lung infections we’re seeing with COVID-19). But ACE-2 is also present in other parts of the body, including the nervous system and vessels going to the brain, Koralnik said.
The other potential mechanism behind the neurological symptoms is called a secondary infection, which means that a person’s respiratory infection is putting so much strain on the body that it’s triggering a major neurological problem.
“For example, if somebody has difficulty breathing and they don’t get enough oxygen in their body and their brain, then they will have altered mental function,” Koralnik said.
Pneumonia and acute respiratory distress syndrome, two severe complications observed in people with COVID-19, can cause multiple organ failure, which can damage the brain.
“The brain is the organ that suffers the most from lack of oxygen,” Koralnik said.
Neurological symptoms may be even more likely in infected people with chronic health issues, Arora said. Many people who are coming down with a more serious form of COVID-19 already have underlying risk factors, such as high blood pressure or heart disease. COVID-19 likely worsens preexisting health issues and can therefore trigger strokes, seizures or altered consciousness, Arora added.
As with all things COVID-19, we need more research
It’s going to take some time before scientists have a clear understanding of COVID-19’s impact on the nervous system.
Right now, health care providers are so focused on helping patients recover that the neurological component has taken a backseat, making it difficult to determine the actual rate of COVID-19’s impact on the nervous system.
“We in the hospital, throughout the nation — our goal is to get these patients better and get them out of there, so we are limiting on necessary testing. We’re not doing MRI scans and research studies on all of these [COVID-19] patients,” Arora said.
In the meantime, experts hope these early findings can help physicians screen for neurological symptoms to better diagnose and treat people with the coronavirus.
“It’s a caution and a message to neurologists and primary care doctors that if someone comes to you with just these symptoms — loss of taste, loss of smell, muscle problems — think about how that could be a presentation of COVID even though they don’t have fever, cough and all those other things,” Arora said.
Though headaches and loss of taste and smell may seem harmless, they could potentially lead to more serious neurological complications. At the very least, these symptoms may be an indicator that someone is sick and should stay home.
“It’s certainly a red flag,” Koralnik said of any neurological symptom. “It may be the first symptoms that they have, so it would be [wise] to isolate them from anybody else in their household because they could be infectious at that time.”
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