Fever, cough and difficulty breathing may be the symptoms most commonly associated with the new coronavirus, but more reports are surfacing about COVID-19’s effects on the brain in some patients.

Dr. Sara Hocker, a Mayo Clinic neurologist and critical care specialist, discussed Monday with the Leader-Telegram what doctors worldwide are reporting about the potential neurological impacts of COVID-19, including stroke, and what that means for people who may experience such symptoms.

The interview has been edited and condensed.

Much has been reported about the fever and respiratory symptoms associated with COVID-19. What neurological symptoms also are being seen in COVID-19 patients?

There are several different groups of patients with neurological symptoms. One is what we’ve seen from the beginning, with our patients who have headaches, nausea, vomiting, sometimes confusion or neck stiffness. These patients have what’s called encephalitis, or inflammation of the brain, or meningitis, which is inflammation of the tissues that surround the brain.

The second group we see less commonly are patients who develop severe weakness, starting typically in the legs and then moving to the arms with a loss of reflexes. This seems to be very similar to what is known as Guillain-Barré syndrome, which is paralysis due to injury to the nerves that typically occurs about two weeks after an infection or vaccination. However, with COVID-19, we’re seeing this not only after infection but sometimes preceding the infection. This is not yet fully understood.

The third group of patients are those developing strokes in association with a COVID-19 infection. These are very concerning to us because they are occurring in younger patients than what we’re used to seeing for the general stroke population. They are disabling strokes. They are blockages of larger arteries and therefore feed larger territories of brain.

Are these neurological symptoms believed to be long-term or permanent?

If the vessel is not opened quickly and/or the patient doesn’t have what we call good collateral vessels, and younger patients typically don’t, then it will be disabling and permanent.

What message should people take from these reports?

The main message I’d like to get across is that patients who develop sudden onset of stroke symptoms should be calling 911. The (U.S. Centers for Disease Control and Prevention) recommends that we call our doctors about symptoms before going to the emergency department unless they are severe because we don’t want people showing up healthy to the emergency department and potentially getting exposed to the virus. But this is a situation where that is not the recommendation.

If you develop sudden onset weakness, numbness, loss of vision, loss of ability to understand speech or to speak, drooping of the face or any of these sudden onset symptoms that potentially are stroke symptoms, you should call 911. If a patient comes in early with a stroke (caused by a large vessel blockage), which is what primarily has been reported with COVID-19, we can try to open that vessel.

Are some of these effects showing up before what might be considered traditional symptoms of COVID-19?

That is true. However, in some cases, patients have had strokes and a positive result in COVID-19 testing but never developed the other symptoms.

Which of the neurological effects associated with some coronavirus cases are most alarming?

That is something that’s probably very personal to the individual patient. A chef, perhaps, might find the loss of sense of smell to be incredibly disabling. And, of course, meningitis or encephalitis can cause disability. So can stroke and Guillain-Barré syndrome. They can all be life-changing events.

Why do you think the coronavirus also has effects on the nervous system?

That’s a good question and one that we do not have an exact answer to yet. There are theories, and it may be different for each problem. But in general (neurological effects) of systemic disease happen either because of direct invasion of the virus or because of the body’s immune or inflammatory response to the virus.

Are these neurological symptoms a new development?

The headache, nausea and vomiting have been reported since China, since this started. The less common complications probably just took longer to be recognized. We needed to see more patients in order for it to become clear that this was an association with the virus and not just coincidence.

Does some of this pose a risk to doctors who might think they’re just dealing with a stroke patient and not realize their potential exposure to COVID-19?

We cannot eliminate all risk. However, right now our approach is to approach every patient as though they may have COVID-19 and use universal precautions and personal protective equipment following the CDC’s and our own institution’s guidelines, so we have really good protections in place for our health care staff.

Do these revelations suggest there is still a lot to learn about this virus?

Yes. We are learning every day. There is new information coming out every day, and that will likely continue throughout this pandemic.