Experts grapple with COVID-19 brain harm

More research needed to understand lasting cerebral consequences of virus

Scientists in the United Kingdom are leading twin national and international projects to try and find out how and why COVID-19 damages the brain.

While COVID-19 is commonly associated with respiratory problems, many patients also develop neurological symptoms, which in some cases can lead to severe and long-lasting complications.

Some of the brain conditions patients have suffered include stroke, delirium and encephalitis, or swelling on the brain.

Benedict Michael, a neurologist at the University of Liverpool and co-lead on the new UK-wide study, says that the root cause of certain conditions remains unclear, highlighting the need for more research.

"COVID-19 patients frequently suffer brain complications during the infection and are left with brain injuries which can have lifelong consequences," said Michael. "Similar problems have been seen in previous pandemics, including Spanish influenza over 100 years ago, but how and why this occurs remains poorly understood."

Liverpool and King's College universities will oversee the national study, which was awarded a 2.3 million-pound ($3 million) grant from the UK government.

The researchers will look at 800 patients who were admitted to UK hospitals with COVID-19 and had neurological or neuropsychiatric complications, to understand how these problems occur and develop strategies to prevent and treat them.

COVID-19 infection can cause small clots to develop in blood vessels, and these clots sometimes travel to the brain, leading to stroke. A systematic review led by Western University in Canada and published last month in the journal Neurology found that 1.8 percent of admitted COVID-19 patients suffer from strokes.

There have also been reported cases of encephalitis among COVID-19 patients. This condition is linked to inflammation on the brain, which in turn can cause seizures and impaired speech.

"We want to compare patients with these complications to similarly ill hospitalized patients who did not have these problems," said Gerome Breen, a professor of psychiatric genetics at King's College London and co-lead on the study. "We will monitor their outcomes and integrate social and environmental risk factors into our analyses alongside all the biology information we will measure."

COVID-19 has also been linked to debilitating forms of nerve issues elsewhere in the body, with some patients experiencing decreased motor function in the limbs.

One potential explanation for extreme inflammation and resultant nerve damage is cytokine storm, where an exaggerated response from a hyperactive immune system can affect nerves and other tissues.

In an additional project announced last week, Liverpool will lead an international study of COVID-19 related brain conditions. The study will look at patient data from around the globe, and also carry out studies in hospitals in Malawi, Brazil and India.

UK government agencies have awarded 860,000 pounds to the project, which will be co-led in India by Ravi Vasanthapuram, a professor at the National Institute of Mental Health and Neurosciences in Bangalore.

Vasanthapuram said the project will "delve deeper into the effects COVID-19 has on the brain" and look to improve care for "people across India and other low-and middle-income countries".