How COVID-19 can damage the brain

Some people who become ill with the coronavirus develop neurological symptoms. Scientists are struggling to understand why.

The woman had seen lions and monkeys in her house. She was becoming disoriented and aggressive towards others, and was convinced that her husband was an impostor. She was in her mid-50s — decades older than the age at which psychosis typically develops — and had no psychiatric history. What she did have, however, was COVID-19. Hers was one of the first known cases of someone developing psychosis after contracting the disease1.

Neurological effects

In the early months of the COVID-19 pandemic, doctors struggled to keep patients breathing, and focused mainly on treating damage to the lungs and circulatory system. But even then, evidence for neurological effects was accumulating. Some people hospitalized with COVID-19 were experiencing delirium: they were confused, disorientated and agitated2. In April, a group in Japan published3 the first report of someone with COVID-19 who had swelling and inflammation in brain tissues. Another report4 described a patient with deterioration of myelin, a fatty coating that protects neurons and is irreversibly damaged in neurodegenerative diseases such as multiple sclerosis.

“The neurological symptoms are only becoming more and more scary,” says Alysson Muotri, a neuroscientist at the University of California, San Diego, in La Jolla.

The list now includes stroke, brain haemorrhage and memory loss. It is not unheard of for serious diseases to cause such effects, but the scale of the COVID-19 pandemic means that thousands or even tens of thousands of people could already have these symptoms, and some might be facing lifelong problems as a result.

Yet researchers are struggling to answer key questions — including basic ones, such as how many people have these conditions, and who is at risk. Most importantly, they want to know why these particular symptoms are showing up.

Post Covid-19 program at the Institut Guttmann

The new post-Covid-19 Neurorehabilitation Program of the Institut Guttmann has as its main objective the early detection and treatment of these sequelae and includes functional, neurological-motor, cognitive-behavioral, emotional and respiratory rehabilitation. The program alternates face-to-face and telematic medicine and includes a prior assessment of the patient’s condition and personalized treatment by a transdisciplinary team made up of neurorehabilitation doctors, physiotherapists, occupational therapists and physical educators, neuropsychologists and access to the cognitive telerehabilitation platform. Guttmann, NeuroPersonalTrainer®.

Affected brains

Although viruses can invade and infect the brain, it is not clear whether SARS-CoV-2 does so to a significant extent. The neurological symptoms might instead be a result of overstimulation of the immune system. It is crucial to find out, because these two scenarios require entirely different treatments. “That’s why the disease mechanisms are so important,” says Benedict Michael, a neurologist at the University of Liverpool, UK.

As the pandemic ramped up, Michael and his colleagues were among many scientists who began compiling case reports of neurological complications linked to COVID-19.

In a June paper5, he and his team analysed clinical details for 125 people in the United Kingdom with COVID-19 who had neurological or psychiatric effects. Of these, 62% had experienced damage to the brain’s blood supply, such as strokes and haemorrhages, and 31% had altered mental states, such as confusion or prolonged unconsciousness — sometimes accompanied by encephalitis, the swelling of brain tissue. Ten people who had altered mental states developed psychosis.

Not all people with neurological symptoms have been seriously ill in intensive-care units, either. “We’ve seen this group of younger people without conventional risk factors who are having strokes, and patients having acute changes in mental status that are not otherwise explained,” says Michael.

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