What we know about how the coronavirus affects the brain

Nearly half a year into the COVID-19 pandemic, it’s becoming clear that the coronavirus is not just a respiratory infection.

In addition to wreaking havoc on patients’ lungs, researchers are also seeing evidence that the coronavirus affects the brain in some patients. Such complications are rare, but potentially serious, including delirium, strokes, and, in some cases, even fatal brain swelling.

How the Coronavirus Affects the Brain

In just the past couple of weeks, several studies have been published about how the coronavirus affects the brain and nervous system.

In The Lancet Psychiatry on June 25, a team of researchers investigated how many patients in the U.K. received both new diagnoses for COVID-19 and a neurological or psychiatric condition that required hospitalization.

Over a three-week period, 153 such patients turned up at 64 hospitals that agreed to participate in the study.

“(W)e were surprised to identify quite so many cases, particularly in younger patients, and by the breadth of clinical syndromes ranging from brain inflammation (encephalitis) through to psychosis and catatonia,” researcher Benedict Michael said in a press release.

That new insight into how the coronavirus affects the brain and nervous system inspired the researchers to start looking at the situation beyond the U.K.’s borders — their subsequent analysis of studies from the U.S., China, and other nations turned up 1,000 cases similar to those in the U.K.

On July 8, researchers from University College London (UCL) published a study in the journal Brain detailing the cases of 43 COVID-19 patients who experienced brain and nervous system complications.

Of those patients, nine were diagnosed with ADEM, a rare and potentially fatal brain swelling that usually affects children.

The team behind the study told Reuters that, prior to the COVID-19 pandemic, they treated one adult ADEM patient a month at their London clinic — during the course of their study, at the height of the London outbreak, they saw at least one per week.

The Hunt for Answers

The increase in ADEM cases noted by the UCL team is just one of the patterns now emerging as researchers attempt to understand how the coronavirus affects the brain.

But for seemingly every new insight they glean, new questions emerge: How does the coronavirus cause brain damage? Does the virus attack the brain directly, or is it an indirect effect? Is it preventable? What are the long-term implications, if any?

We want clinicians to be alert to these coronavirus complications.

Michael Zandi

Like so much about the coronavirus, it’s still too soon to know what the answers to those questions will be.

For now, researchers are hopeful that their studies will encourage doctors to keep an eye out for potential brain damage and neurological problems while treating COVID-19 patients.

“We want clinicians around the world to be alert to these complications of coronavirus,” Michael Zandi, a senior author of the UCL study, told The Guardian.

“The brain does appear to be involved in this illness,” he added.

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