Confusion, seizure, strokes: How Covid-19 may affect the brain

A pattern is emerging among Covid-19 patients arriving in New York hospitals: beyond fever, cough, and shortness of breath, some are profoundly disoriented to the point of not knowing where they are or what year it is.

Sometimes this is related to low blood oxygen levels, but in some patients the confusion seems disproportionate as to how their lungs are doing.

Jennifer Frontera, a neurologist at NYU Langone Brooklyn Hospital who cares for these patients, said AFP The findings raised concerns about the impact of the coronavirus on the brain and nervous system.

Right now, most people are familiar with the respiratory characteristics of Covid-19 disease that has infected more than 2.2 million people worldwide.

But more unusual signs appear in the new front-line reports.

Read: What happens to the body when it becomes infected with Covid-19?

A study published in the Journal of the American Medical Association last week found that 36.4 percent of the 214 Chinese patients had neurological symptoms ranging from loss of smell and nerve pain, to seizures and strokes.

An article in the New England Journal of Medicine this week examining 58 patients in Strasbourg, France, found that more than half were confused or agitated, and brain imaging suggests inflammation.

"You've been hearing that this is a respiratory problem, but it also affects what matters most to us, the brain," said Andrew Andrewson, chair of the department of neurology at the University of California, San Francisco. AFP.

"If you get confused, if you have trouble thinking, those are reasons to seek medical attention," he added.

"The old mantra of 'Don't come in unless you're out of breath' probably won't apply anymore."

Viruses and the brain

It is not entirely surprising to scientists that SARS-CoV-2 can affect the brain and nervous system, as this has been documented in other viruses, including HIV, that can cause cognitive decline if left untreated.

Viruses affect the brain in one of two main ways, explained Michel Toledano, a neurologist at the Mayo Clinic in Minnesota.

One is to trigger an abnormal immune response known as a cytokine storm that causes inflammation of the brain, called autoimmune encephalitis.

The second is a direct infection of the brain, called viral encephalitis.

How can this happen?

The brain is protected by something called a blood-brain barrier, which blocks foreign substances but could break if compromised.

However, since loss of smell is a common symptom of the coronavirus, some have hypothesized that the nose could be the way to the brain.

This remains unproven, and the theory is somewhat weakened by the fact that many patients who experience anosmia do not have severe neurological symptoms.

In the case of the new coronavirus, doctors believe that based on current evidence, neurological impacts are more likely the result of an overactive immune response rather than a brain invasion.

To prove that the latter happens, the virus must be detected in the cerebrospinal fluid.

This has been documented once, in a 24-year-old Japanese man whose case was published in the International Journal of Infectious Disease.

The man developed confusion and seizures, and the images showed that his brain was inflamed. But since this is the only case known so far, and the virus test has not yet been validated for cerebrospinal fluid, scientists remain cautious.

More research is needed

All of this emphasizes the need for more research.

Frontera, who is also a professor at New York University School of Medicine, is part of an international collaborative research project to standardize data collection.

Her team is documenting surprising cases including seizures in Covid-19 patients with no history of episodes and new "unique" patterns of small brain hemorrhages.

A surprising finding concerns the case of a man in his fifties whose white matter, the parts of the brain that connect brain cells to each other, was so severely damaged that it "would basically put him in a state of deep brain damage," he said. . .

Doctors are puzzled and want to use their cerebrospinal fluid to obtain a sample.

Brain imaging and spinal strokes are difficult to perform in ventilator patients, and since most die, the full extent of neurologic injury is not yet known.

But neurologists are being called in for the minority of patients who survive on a ventilator.

"We are seeing a lot of patient consultations presenting in confused states," said Rohan Arora, a neurologist at Long Island Jewish Forest Hills Hospital. AFP, saying it describes more than 40pc of recovered virus patients.

It is not yet known if the deterioration is long term, and being in the ICU can be a disorienting experience as a result of factors including strong medications.

But getting back to normal seems to be taking longer than for people with heart failure or stroke, Arora added.

Headline: Thailand's Minister of Health, Anutin Charnvirakul (R), views closed-circuit video footage at the Bamrasnaradura Institute for Infectious Diseases, outside Bangkok, where they confine patients infected with coronavirus. – AFP / Archive