Even mild Covid can ‘destroy your brain 18 months after infection’ – causing memory loss and attention deficit

EVEN a mild Covid infection can take a toll on your memory and attention, scientists say – with effects lingering up to 18 months later.

It’s not just people who survived a severe bout of Covid-19 that can be left battling “brain fog”.

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People who had mild Covid infections can still experience lingering cognitive symptoms months afterwards[/caption]

A new study conducted by scientists at the University of São Paulo in Brazil found that those who weathered only mild infections were still left with cognitive impairments months after their illness.

They collected data from 302 volunteers who’d had mild, moderate or severe cases of Covid.

Researchers assessed their IQ, attention, memory, processing speed, as well as symptoms of depression, anxiety, and stress, at least eighteen months after infection.

All three groups reported lingering memory loss and trouble with concentration.

As might be expected, these symptoms were most severe in patients who’d suffered a severe infection, with just under 50 per cent reporting cognitive impairment.

Thirty-nine per cent of people who’d had a moderate bout of Covid said they had residual impacts to their memory and attention.

But 11.7 per cent of those who’d had minimal Covid symptoms still reported lingering cognitive impacts in the months after being recovering from their illness.

Researchers did note that “cognitive difficulties may diminish over time in milder cases”, based on their results.

“We showed that cognitive symptoms persist in mild cases and are even more prevalent in individuals with severe manifestations,” they wrote in the paper published to BMC Psychology.

“Furthermore, we confirmed our central hypothesis: people with severe forms of Covid-19 show diminished cognitive performance 18 months after infection compared to those with mild to moderate forms.”

They added: “While cognitive difficulties can vary from person to person, and other factors may influence these results, it is suggested that Covid-19 significantly contributes to mental challenges associated with long-term symptoms.”

Participants in the study with poor memory and attention test scores said they had difficulties with recalling words or performing routine activities, such as forgetting pots on the stove or failing to pick children up from school.

Antônio de Pádua Serafim, study author and a professor at the Institute of Psychology, said: “Although the damage done by the disease in terms of memory loss, attention deficit and slow processing increases in proportion to its severity, the same problems affect a far from negligible number of people – around 100 in our study – who had mild or moderate COVID.

Researchers said they results showcase the potential impact of neuroinflammation – an inflammatory response in the brain triggered by injury or infection – following a Covid-19 infection.

Prof Serafim added: “Memory loss and attention deficit are known to be associated with post-intensive care syndrome due to intubation under deep anaesthesia.

“Some of the data analysed in the study, however, was from patients who didn’t require intensive care or didn’t even have sufficient symptoms to be hospitalised and nevertheless exhibited memory loss and attention deficit.

“The findings therefore opened our eyes to the question of neuroinflammation due to Covid-19.”

The study author said problems with attention could have a “huge impact on people’s daily lives”.

“High-quality attention is required to think and act in various ways at the same time. Impairment of attention in turn affects memory.

“In some cases, attentional activity is so dispersed that […] the person can’t remember what they were doing.

“This also affects processing activity, which involves rapid decision-making based on information.”

‘Not a closed case’

Though “the severe phase of the pandemic is over”, this is “not a closed case”, the professor argued.

“However, we don’t have an effective program to intervene not only in the emotional aspects but also in the cognitive difficulties resulting from COVID-19.”

According to Prof Serafim, it’s been clear for some time that Covid can affect the central nervous system as well as the lungs, kidneys, heart and muscles.

But he said extent of the damage it may cause is not well understood. 

“We don’t know if cognitive impairment due to COVID-19 is permanent, and we’re currently evaluating ways to intervene in this process,” he stated.

Dr Serafim said more effort needs to be made in rehabiltating people after Covid to address the lingering cognitive effects of the virus.

He and other University of São Paulo researchers are now developing programmes to try and ease the cognitive impacts of Covid infections.

They’re testing out non-invasive techniques that aim to improve brain function, such as neurostimulation – electrical stimulation of the nerves – and neurofeedback, a therapy often used as treatment for attention-deficit/hyperactivity disorder (ADHD) that aims to change the way the brain responds to certain stimuli.

“We have only case studies so far. For example, in the case of a physician who was in the intensive care unit for 34 days, we conducted a neurofeedback protocol often used to study patients with attention deficit disorder, and he made a good recovery.

“But that was an isolated case,” Dr Serafim said.

“Based on the knowledge we’ve acquired so far regarding cognitive stimulation and rehabilitation techniques, I believe it may be possible to obtain an improvement in neural connectivity by means of brain training to stimulate overall cognitive ability.”