Covid infection also affects brains of people with no pre-existing neurological conditions, finds a study.
While many people showed improvement, the majority still had some neurological symptoms six months after a Covid infection. But some individuals also exhibited significant coordination and cognitive issues, which had not been previously described, said researchers from the University of California-San Diego.
None of these individuals with persistent symptoms at six months had any history of pre-existing neurological conditions prior to their SARS-CoV-2 infections.
They displayed a previously unidentified set of symptoms that included cognitive deficits, tremor and difficulty balancing, explained the team in the paper published in Annals of Clinical and Translational Neurology.
"These are folks who had no neurological problems before Covid-19, and now they have an incoordination of their body and possible incoordination of their thoughts," said senior author Jennifer S. Graves, Associate Professor at UC San Diego School of Medicine and neurologist at UC San Diego Health.
Researchers are still investigating how much the SARS-CoV-2 virus directly invades the brain, but Graves said it is more likely that these delayed neurological symptoms are caused by the infection triggering an inflammatory autoimmune response in the brain.
In the study, the team included 56 persons with neurological symptoms following mild-to-moderate SARS-CoV-2 infections between October 2020 and October 2021.
They completed a neurological exam, cognitive assessment, self-reported questionnaires and an optional brain scan. Baseline measurements were taken a few months after their initial infection and repeated three and six months later.
At the time of their first visit, 89 per cent of participants were experiencing fatigue and 80 per cent reported headaches. Besides fatigue and headaches, other common neurological symptoms included memory impairment, insomnia and decreased concentration. Eighty per cent of participants said these symptoms impacted their quality of life.
When participants returned for their six-month follow-up, only one-third reported complete resolution of symptoms. The other two-thirds of participants reported persistent neurological symptoms, though most had diminished in severity. The most prevalent symptoms at six months were memory impairment and decreased concentration. About 7 per cent presented with the unidentified set of symptoms.
"It's encouraging that most people were showing some improvement at six months, but that wasn't the case for everyone," said Graves.
"Some of these participants are high-level professionals who we'd expect to score above average on cognitive assessments, but months after having Covid-19, they're still scoring abnormally," she added.