New research has found that one worrying symptom of Covid-19 can be seen in people who suffered even a mild case of the virus for months after recovery.
Researchers at the University of Oxford found that people who were diagnosed with Covid suffered from attention and memory problems for a prolonged period after recovery.
Previous studies have shown that after severe Covid infection, some people can continue to suffer from cognitive symptoms such as difficulties in concentrating, also known as brain fog, as well as forgetfulness and fatigue and other symptoms of long Covid’ syndrome.
However, up until now, it was not known if cognitive performance could also be affected in individuals who had mild symptoms of Covid and have not reported other symptoms of long Covid.
The study found that people who reported no other symptoms of long Covid still had difficulties with their memory up to six to nine months.
Participants were asked to complete a number of cognitive tests which focused on attention, memory, planning and semantic reasoning.
Their results in the short term memory and planning tests compared well with the control group. However, they scored noticeably less when asked to recall past events, and their ability to remain focused over time was also less than the control group.
All the participants had previously suffered from Covid-19 but were not significantly different from a control group at the time of testing on factors such as fatigue, forgetfulness, sleep patterns or anxiety.
Although there does not seem to be any cause for concern as most people’s memory and attention span returned to normal after six to nine months.
Dr Sijia Zhao of the department of experimental psychology 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 6-9 months after infection, who demonstrated good recovery over time.”
