What's Causing Neurological Symptoms In COVID-19 Patients?

As scientists continue discovering more about COVID-19 and its devastating effects on the body, researchers are now taking a closer look at the virus’s impact on the nervous system. 

A new study published this month in the Annals of Clinical and Translational Neurology recognized a wide range of neurological symptoms in COVID-19 patients, and found that “evidence of their severity and persistence is increasing." The study highlights the high frequency and range of neurologic manifestations, “which occurred in more than four-fifths of COVID-19 patients hospitalized in our hospital network system," the authors wrote. 

Researchers involved in this study analyzed the charts of more than 500 hospitalized COVID-19 patients within the Northwestern Medicine Health System in Illinois.

• 32% experienced encephalopathy—or brain damage and dysfunction
• 30% experienced dizziness
• 45% experienced muscle aches
• 38% experienced headaches
• 16% lacked a sense of taste
• 11% reported a loss in sense of smell

According to Wilfred G. van Gorp, PhD, ABPP, a board-certified neuropsychologist and director of the Cognitive Assessment Group, who was not involved with the study, the neurological COVID-19 symptoms he’s seeing in patients are showing up indiscriminately.

“There’s not one cognitive signature of COVID-19 in terms of brain function,” he tells Verywell. “For some people, it's this brain fog that we’re hearing a lot about. Some patients report very focal symptoms like weakness on the right side of the body, [and later] they receive a CAT Scan that shows no sign of a stroke. Some are plagued by terrible headaches or very prominent emotionality similar to what we see in concussion patients. It’s a moving target and that’s what’s making it hard for clinicians.”

What Causes Neurological Symptoms?

Because COVID-19 research is still underway, there are still many unknowns about how it will affect patients long-term. Based on what van Gorp is currently seeing in his own patients, he predicts many exhibiting COVID-19-related cognitive impairment are experiencing hypoxia, which happens when a certain region of the body is deprived of adequate oxygen. 

“In theory, if there’s hypoxia in the brain and it resolves, those symptoms will likely get better,” he says. “However, there is a subset of patients who do have almost a chronic fatigue-like brain fog and it may just be persistent somewhat indefinitely. That seems to be what’s appearing. We just don’t have the prospective studies to speak on it definitely yet. There are so many unknowns.”

Mahesh Jayaram, MD, a senior lecturer in the department of psychiatry at the University of Melbourne, tells Verywell there are three possible mechanisms that would lead a COVID-19 patient to develop neurological symptoms:

• Direct neuronal effect where the virus invades the nervous system via the olfactory nerve
• Inflammation mediated damage caused by an overreaction of the body’s immune system
• Coagulation induced damage caused by an increased risk of clotting and stroke

“The more severe the COVID-19 infection, the more likely the person is going to experience neurological symptoms,” Jayaram says. “We know that the rates of neurological symptoms vary but can be as high as 84%. Age, hypertension, diabetes, obesity, and other pre-existing medical conditions are all thought to be risk factors for more severe infections.”

How Long Can Symptoms Last?

It's still too early to know exactly how long neurological symptoms will persist, Jayaram says, adding that we should assume at this early stage in our knowledge of the virus that long-term or permanent effects could be a possibility. 

“We need to evaluate in ongoing longer-term studies how long it would take for the inflammatory changes in the brain to subside and for mental health conditions to improve, which will all contribute to the brain fog clearing up,” he says. “Features like anosmia (loss of smell) tend to clear up, however fatigue and memory issues may persist longer term."

Jayaram says that for many, the long-term effects have proved life-changing.

"There are reports emerging that people are less likely to go back to their previous employment, less able to perform physically in sports and other activities compared to pre-infection," he says. "Although COVID-19 predominantly affects the respiratory system, it also affects multi-organ systems including the brain by hitherto ill-understood mechanisms.”

For COVID-19 patients who already suffer from chronic neurological disorders like multiple sclerosis, Bell’s palsy, or Parkinson’s disease, Van Gorp says more is at stake.

“There’s no research study on which to base an opinion, but [If a patient has a chronic neurological disorder already] the question will be whether or not the effects are additive or interactive,” he says. “Let’s take multiple sclerosis. Some MS patients use wheelchairs and many use a cane. Then, many have a cognitive impairment as part of their condition. Now, if they get COVID-19 and recover, they’ll have this physical fatigue in addition to a motor and coordination issue."

The treatment for COVID 19-related neurological problems, van Gorp says, starts with monitoring oxygen levels to prevent hypoxia and ruling out focal brain lesions caused by stroke. The doctor may or may not decide to put a patient on blood thinners to prevent any coagulation sparked by COVID-19 that could potentially lead to a stroke. When it comes to brain fog, a psychostimulant medication could help address symptoms and clear up any cloudiness.

"It’s not a very rosy outcome for a lot of people, I’m afraid," van Gorp says.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.