Researchers at University of California San Diego School of Medicine are conducting a longitudinal study to track neurological symptoms in COVID-19 “long-haulers.”
The first round of results revealed the prevalence of various short- and long-term symptoms and found that, while many patients showed improvement, the majority still had some neurological symptoms after six months. A subset of individuals also exhibited significant coordination and cognitive issues, which had not been previously described.
Following mild-to-moderate SARS-CoV-2 infections, 56 persons with neurological symptoms were recruited to the study 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 percent of participants were experiencing long-haulers symptons like fatigue and 80 percent reported headaches. Other common neurological symptoms included memory impairment, insomnia and decreased concentration. Eighty percent 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. None of the individuals with persistent symptoms at six months had any history of pre-existing neurological conditions prior to their SARS-CoV-2 infections.
Seven percent of participants displayed a previously unidentified set of symptoms that included cognitive deficits, tremor and difficulty balancing. The authors labeled the phenotype Post-Acute Sequelae of COVID-19 infection with Tremor, Ataxia and Cognitive deficit (PASC-TAC). 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.
Researchers are still investigating how much the SARS-CoV-2 virus directly invades the brain, but researchers believe it is more likely that these delayed neurological symptoms are caused by the infection triggering an inflammatory autoimmune response in the brain.
The team plans to continue monitoring long-haulers participants’ symptoms annually for up to 10 years. Additional efforts will evaluate how different COVID-19 variants and vaccines affect long-term neurological symptoms. To have people’s cognition and quality of life still impacted so long after infection is something we as a society need to be taking a serious look at. We still need to know how common this is, what biological processes are causing this, and what ongoing health care these people will need. This work is an important first step to getting there.