Over 80% of Hospitalized Patients With COVID-19 Develop Neurological Problems

About 82% of patients hospitalized with COVID-19 developed neurological problems, according to the largest study to date looking at COVID-induced neurological manifestations. Headaches were the most commonly reported neurological problem followed by loss of taste and smell.

The Research

The international study, which was published in JAMA Network Open in May, found that people with neurological symptoms were six times more likely to die from COVID-19.

Lead study author Sherry H.-Y. Chou, MD, MSc, an associate professor of critical care medicine, neurology, and neurosurgery at the University of Pittsburgh, tells Verywell that they believe that the correlation between neurological problems and an increased mortality rate likely comes from detecting it too late.

Part of the reason is that there are not enough neurological subspecialists; what Chou calls "a limited resource." To that end, Chou says that with the new study, the researchers "wanted to make sure that we find a way to capture the magnitude of the problem and any impact on the nervous system so that we can appropriately direct resources to the patients who need them and not miss them."

Chou also points out that patients who are very ill may not even notice neurological symptoms until later on. "And presumably, if we find it earlier, we figure it out earlier," says Chou. "So, we have a chance to treat it earlier with limited long-term damage.”

How the Study Was Done

In collaboration with the GCS-NeuroCOVID Consortium and the ENERGY Consortium, the study is the most extensive to date looking at neurological problems in people with COVID-19. It involved 133 sites spanning 4 continents and 13 countries.

The researchers recruited patients who were hospitalized with severe COVID-19. The study ultimately included:

• 3,055 patients with COVID-19 regardless of neurological status,
• 475 patients with confirmed COVID-induced neurological problems, and
• 214 patients who had required evaluation by a consulting neurologist to participate in the study.

Patients reported any neurological problems that they experienced while they had COVID. Any evidence of a neurological condition was also recorded by the doctors monitoring the patient's symptoms.

What the Study Found

Of the 3,743 patients who were hospitalized with COVID, 3083 (82%) developed a neurological problem. Headaches were reported more than any other neurological symptom (37%). The second highest self-reported symptoms were loss of smell or taste (from 26% of patients).

The researchers found that the people who reported headaches, loss of smell and taste, or muscle weakness had a lower risk of dying from COVID-19. However, Chou clarifies that the results do not suggest that headaches protect people from dying from COVID.

Chou says that the association might be because patients who can talk about their symptoms are in much better condition than patients who cannot speak. Also, headaches are subjective and self-reported; therefore, it would be harder for doctors or researchers to diagnose a headache in a nonverbal patient.

“With symptoms like headache, we rely on the patients telling us that they're experiencing this," says Chou. "If the patient is unable—because they're critically ill and on a ventilator or if they have other neurological symptoms where they don't have the mental faculties to tell us—then we wouldn't know they have a headache, even if they're experiencing it."

While headaches are on the milder side of the spectrum, Chou says that it’s an important symptom and one that could affect a person’s quality of life or warrant a trip to the hospital.

“In this patient population we studied, these are patients who are sick enough to need to be admitted to a hospital," says Chou. "By definition, they have severe or critical COVID. That's not to say that their headaches are not important. This is not to say that [headaches] don't cause morbidity. From other studies, we know that a lot of people who have survived COVID have long-lasting neurological symptoms, and headaches are one of them."

Future Research on Long COVID

The initial study focused on adults, but Chou says that the team is now collecting data on neurological issues in pediatric patients, which are currently being analyzed and will be published soon.

While the first study recruited and collected information from about 3,700 adult patients, Chou says that data on adult patients continues to come in even after the paper’s publication. Their continued analysis—which is now up to 4,000 patients—will give them a larger data set to confirm what they found in the initial study’s results.

Chou says that even though having a vaccine will help curb COVID, they are concerned about the millions of COVID survivors who are living with neurological issues that were caused by the virus.

The next step for researchers will be to gather more data on the neurological effects of COVID after hospital discharge.

“We need to know how the survivors are doing," says Chou. "For those who ‘beat’ COVID: is it happily ever after or are we talking about [neurological] problems that built up and didn’t go away even after they leave the hospital? Because we've seen that as well."