The novel coronavirus pandemic could lead to a wave of brain damage in infected patients, warned British researchers in a new study released Wednesday.
Experts at the University College London (UCL) were the latest to describe that Covid-19 could cause neurological complications including stroke, nerve damage, and potentially fatal brain inflammation -- even if the patients didn't show severe respiratory symptoms associated with the disease.
"We should be vigilant and look out for these complications in people who have had Covid-19," said joint senior author Dr. Michael Zandi, warning that it remains to be seen "whether we will see an epidemic on a large scale of brain damage linked to the pandemic."
The study, published in the journal Brain, examined 43 patients treated at University College London Hospitals for either confirmed or suspected coronavirus, from April to May. They varied in age from 16 to 85, and showed a range of mild to severe symptoms.
Among these patients, researchers found 10 cases of "temporary brain dysfunction" and delirium; 12 cases of brain inflammation; eight cases of strokes; and eight cases of nerve damage.
Most of the patients who showed brain inflammation were diagnosed with a specific, rare and sometimes deadly condition known as Acute disseminated encephalomyelitis (ADEM). Before the pandemic, the research team in London would see about one ADEM patient per month. During the study period, the number rose to at least one a week.
One woman hallucinated lions and monkeys in her house. Others reported numbness in their limbs or face, double vision, and disorientation. One severe patient was barely conscious, responding only when in pain.
Researchers are still trying to figure out why exactly Covid-19 patients are developing these brain complications. The virus that causes Covid-19 was not found in their brain fluid, meaning the virus does not appear to directly attack the brain. One theory, instead, is that the complications are indirectly triggered by an immune response from the patient's body -- not from the virus itself.
These findings are significant for informing how doctors around the world monitor and treat patients -- but they also pose new questions and challenges. For patients who aren't showing severe respiratory symptoms such as trouble with breathing, it can be difficult to identify these brain complications early enough to prevent or minimize damage. And for patients who are critically ill, their precarious health can limit how much doctors can do to investigate what's happening in their brain.