Experts at University College London (UCL) were the last to describe that Covid-19 could cause neurological complications such as stroke, nerve damage and possibly fatal brain inflammation – even if patients did not experience severe respiratory symptoms associated with the disease.
Monitoring studies will be necessary to understand the possible long-term neurological consequences of the pandemic, they said.
The study, published in the journal Brain, looked at 43 patients treated at University College London Hospitals for confirmed or suspected coronavirus from April to May. They varied from 16 to 85 years of age and showed a range of mild to severe symptoms.
Among these patients, the researchers found 10 cases of “temporary brain dysfunction” and withdrawal. 12 cases of cerebral inflammation. eight cases of stroke and eight cases of nerve damage.
Most of the patients who developed inflammation of the brain were diagnosed with a specific, rare and sometimes fatal condition known as acute diffuse encephalomyelitis (ADEM). Prior to the pandemic, the research team in London would see about one ADEM patient per month. During the study period, the number increased to at least one per week.
A woman was ill-treated by lions and monkeys in her home. Others reported numbness in their limbs or face, double vision, and disorientation. A serious patient was almost unconscious, responding only to pain.
Researchers are still trying to figure out exactly why Covid-19 patients develop these complications in the brain. The virus that causes Covid-19 was not found in their cerebrospinal fluid, which means that the virus does not appear to directly infect the brain. One theory, on the other hand, is that complications are indirectly caused by an immune response from the patient’s body – not the virus itself.
These findings are important for informing physicians around the world about monitoring and treating patients – but they also raise new questions and challenges. For patients who do not have severe respiratory symptoms, such as trouble breathing, it may be difficult to detect these brain complications early enough to prevent or minimize damage. And for seriously ill patients, their precarious health can limit how much doctors can do to find out what’s going on in their brains.
The authors warn that further studies will be “necessary” to understand exactly how the virus causes brain damage and how to treat it.
“Since the disease has only existed for a few months, we may not yet know what long-term damage Covid-19 can cause,” the first author, Dr. Ross Paterson. “Physicians need to be aware of the possible neurological consequences, as early diagnosis can improve patients’ results.”
Dr David Strain of the University of Exeter Medical School, who did not participate in the study, described the findings as significant, but “not surprising” given previous cases of coronavirus.
“The main limitation is that we do not know what the denominator is, so we do not know how often these complications occur,” he said in a statement on Wednesday. “We’ve already seen that some people with Covid-19 may need a long recovery period – both physical recovery and exercise. We need to understand more about the impact of this infection on the brain.”