COVID-19 may be linked to brain complications, study finds, but does it cause them?

A new study has found more evidence of a correlation between severe COVID-19 cases and brain complications, but the researchers say they are still not sure if those complications are directly caused by the disease.

A man standing in a room: Stroke therapy worker Cavan Smith draws the curtains around a patient's bed in the Acute Stroke Unit at Royal Blackburn Teaching Hospital in Blackburn, North West England on May 14, 2020, as National Health Service personnel in Great Britain fight against the new coronavirus pandemic COVID-19.

© HANNAH MCKAY, POOL / AFP via Getty Images
Stroke therapy worker Cavan Smith pulls the curtains around a patient’s bed in the Acute Stroke Unit at Royal Blackburn Teaching Hospital in Blackburn, North West England on May 14, 2020, while service staff National Healthcare in Britain fights against new coronavirus COVID-19 pandemic.

The preliminary study, announced as the first national survey of the neurological complications of the disease, was published in The Lancet Psychiatry this week.

Over the course of three weeks in April, the researchers surveyed 153 hospitalized patients in the UK who had both a confirmed or probable new diagnosis of COVID-19 and a new neurological or psychiatric diagnosis.

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The researchers found that among the 125 patients with complete medical records, 57 had a stroke caused by a blood clot in the brain and 39 had an altered mental state. Among patients with an altered mental state, 10 of the patients had developed psychosis, a “break from reality,” and seven had encephalitis or inflammation of the brain.

The patients were between 23 and 94 years old. While strokes were more common in older patients, the researchers reported that patients experienced an altered mental state in all age groups.

“While some clinicians reported altered mental status, we were surprised to identify so many cases, particularly in younger patients, and because of the breadth of clinical syndromes,” said Dr. Benedict Michael, who led the study for the University of Liverpool, said in a press release.

The study, while small, helps paint a larger picture of COVID-19’s many types of neurological effects, said Dr. Babak Jahromi, a neurosurgeon at Northwestern Medicine.

“While we have learned in recent months that hospitalized patients with COVID-19 are at increased risk for ischemic strokes, the current study adds to that picture by also showing neuropsychiatric disorders in hospitalized patients with COVID-19,” he said. Jahromi.

The study is the latest in more than 300 published papers looking for a possible connection between COVID-19 and neurological conditions. Several of the studies, including one in China and one in France, found that coronavirus patients frequently reported neurological symptoms. In other reports, autopsies on coronavirus patients in Germany found inflammation in the brain, and autopsies on patients in Massachusetts detected low levels of the virus in the brain.

In the US, news of a possible link between severe COVID-19 and brain complications picked up momentum in April, when New York City doctors reported an increase in strokes in younger patients. Over a two-week period, doctors at Mount Sinai reported that five patients under the age of 50 suffered large strokes, according to a letter they published in the New England Journal of Medicine.

Given the prevalence of coronavirus worldwide, the correlation between severe COVID-19 and brain complications may be a coincidence, said Dr. Robert Stevens, who specializes in critical neurological care at Johns Hopkins Medicine.

“We are seeing this interesting association, but it is very difficult to say, based on this type of result, that COVID causes or explains these neurological symptoms,” said Stevens. Especially with regard to the patients who developed psychosis, “it is really very important, especially in these times when people live in isolation and social distancing, there are many reasons for people to lose it.”

a person in a costume: medical illustration of a brain with symptoms of stroke

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Medical illustration of a brain with stroke symptoms

Stevens said the new Lancet study was valuable because it marks the first systematic effort to characterize neurological and psychiatric conditions in patients with confirmed or suspected COVID-19. It also raises more questions for future study, Stevens said. Who is more susceptible to neurological or psychiatric complications? If the coronavirus is causing brain complications, how is that happening, through direct invasion of cells or by triggering an inflammatory and damaging immune response?

If the coronavirus causes brain complications, that wouldn’t be surprising, Stevens said. Other viral diseases, such as Zika and HIV, are also known to cause brain complications. Several studies have also documented that diseases caused by other coronaviruses (severe acute respiratory syndrome and Middle East respiratory syndrome) caused brain complications.

“It wouldn’t be unexpected,” said Stevens. “But I think it will be a relatively rare event.”

Stevens said he and his team at Johns Hopkins are working with 80 sites around the world to enroll patients in an observational study of the effects of COVID-19 over time.

“If there is indeed a link between COVID and serious complications like stroke and cerebral hemorrhage, the most important question is: what are the long-term effects?” he said. “In the next six to 12 months, we should know a lot more.”

The study authors said their work should alert clinicians to the possibility that COVID-19 patients develop neurological and psychiatric complications.

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One study finds that this article originally appeared in USA TODAY: COVID-19 may be related to brain complications. But does it cause them?