Scientists have warned that we could soon witness a wave of brain disorders following the Covid-19 pandemic.
Mounting evidence suggests that Covid-19 can spark a range of brain disorders and neurological conditions. Reported in the journal Brain, researchers from University College London (UCL) now describe over 40 more cases of people with Covid-19 who suffered temporary brain dysfunction, confusion, strokes, nerve damage, or other serious brain effects.
Most unusually, a number of them did not even suffer from severe respiratory symptoms, meaning the neurological disorder was the first and main presentation of Covid-19.
"We should be vigilant and look out for these complications in people who have had Covid-19,” Dr Michael Zandi, joint senior author from the UCL Queen Square Institute of Neurology, said in a statement. “Whether we will see an epidemic on a large scale of brain damage linked to the pandemic – perhaps similar to the encephalitis lethargica outbreak in the 1920s and 1930s after the 1918 influenza pandemic – remains to be seen,” added Dr Zandi.
The more scientists learn about Covid-19, the more it becomes evident the infection is not a straight-forward respiratory illness. Many case studies have shown that the virus (or, perhaps more precisely, the body's response to the virus) can injure organs other than the lungs, including the heart, kidneys, gut, liver, and – as this new research further shows – the brain.
In the study, the researchers detailed brain disorders found in 43 people (aged 16 to 85) who had either confirmed or suspected Covid-19 while being treated at a hospital in London. In this select group, they identified 12 cases of brain inflammation, 10 cases of temporary brain dysfunction with delirium, eight cases of strokes, eight others with nerve damage, and others with "miscellaneous central disorders who did not fit these categories."
The virus responsible for Covid-19, SARS-CoV-2, was not detected in the cerebrospinal brain fluid of any of the patients tested. This indicates the infection did not directly attack the brain to cause the neurological illness but is perhaps the result of inflammation or another response of the immune system. As mentioned, the researchers warn that this small but significant number of brain disorders sparked by the novel coronavirus suggests the world could be faced with a larger "epidemic" of brain damage.
The 1918 influenza pandemic – a global pandemic that took the lives of between 50 and 100 million people – has been linked (albeit fairly loosely) to an outbreak of brain disease known as encephalitis lethargica “sleeping sickness” in the decade. It is too early to predict whether the ongoing Covid-19 pandemic will lead to a comparable wave of encephalitis lethargica or another brain disorder in the following decade. However, researchers certainly say that’s not impossible.
“Despite the scrutiny on the current pandemic and the near-instantaneous speed of information sharing in the internet age, we have yet to hear of the first case of post Covid-19 encephalitis lethargica and so it seems unlikely these neurological complications will be common symptoms,” remarked Professor Anthony David, director of the UCL Institute of Mental Health, who was not directly involved in the new study.
“But time will tell,” he added.