A MILD bout of Omicron can trigger a nasty side effect for months, experts have warned.
It could interfere with work and daily tasks. But for most, it will be over within a year.
Researchers found “brain fog” plagued people who otherwise had no “long Covid” symptoms, having had the virus previously.
Specifically, they showed attention and memory problems in a series of tests run by Oxford University.
Dr Sijia Zhao of the Department of Experimental Psychology, University of Oxford, said: “What is surprising is that although our Covid-19 survivors did not feel any more symptomatic at the time of testing, they showed degraded attention and memory.
“Our findings reveal that people can experience some chronic cognitive consequences for months.”
Professor Masud Husain said: “We still do not understand the mechanisms that cause these cognitive deficits.
“But it is very encouraging to see that these attention and memory return largely to normal in most people we tested by six to nine months after infection, who demonstrated good recovery over time.”
Previous studies have shown that long-Covid sufferers may get brain fog among other symptoms such as a cough, heart palpitations, muscle aches or insomnia.
Brain fog may include low motivation, lack of focus or attention, poor sleep or other cognitive problems.
However, it was not known if these effects were felt by those who had experienced no other problems since recovering from Covid.
The study involved 136 people, of which 53 people reported they had previously had Covid, mostly mild.
Although they took part in May 2021, when the Delta variant was dominant in the UK, the findings could apply to those who have caught other strains.
Participants in the study were asked to complete a number of cognitive tests, which you can do yourself on the website, with a focus on sustaining attention, memory, planning, and semantic reasoning.
The Covid survivors performed well in short-term working memory and planning compared with the control group.
However, they scored significantly worse in episodic memory and in their ability to sustain attention on a task over time.
Episodic memory is someone’s unique recollection of past events, such as the details of their breakfast or their first kiss, including where and when it happened, and the emotion they experienced.
It was tested by showing participants 20 images, then asking them to recall them at the end of the experiment.
Sustained attention is being able to remain focused on a task for a long period of time.
There was a decline in the Covid participants’ performance in a task lasting nine minutes compared to those who were healthy.
The researchers said it was not clear why Covid caused these problematic brain problems.
But in their paper, published in Brain Communications, they said previous research showed people with the most severe brain problems following Covid had changes in the frontoparietal regions.
These are the brian regions are implicated in episodic memory and sustained attention.
The Covid participants did not have worse scores for factors such as fatigue, forgetfulness, sleep patterns or anxiety at the time of testing.
Other studies have made similar conclusions as Oxford, that people previously infected with Covid are stuck with mind-altering problems.
One study that included researchers from the universities of Imperial College London and Cambridge suggested people lose intelligence following Covid.
In a classic intelligence test, they would have lost the equivalent of seven points in IQ, the team claimed in August 2021.
People who had been on a ventilator during their Covid sickness were most likely to see a decline in scores.
Source: The Sun