Risk of movement disorders, memory problems, strokes, and seizures rose 1 year after acute SARS-CoV-2 infection, an analysis of millions of U.S. veterans' records showed.
Former COVID patients had a 42% increased risk of neurologic problems 12 months after testing positive (HR 1.42, 95% CI 1.38-1.47), reported Ziyad Al-Aly, MD, of Washington University in St. Louis and Veterans Affairs St. Louis Health Care System, and colleagues.
The burden was roughly a 7% increase in long-term neurologic problems (70.69 per 1,000 persons, 95% CI 63.54-78.01), the researchers wrote in . Risks and burdens were elevated even in people who did not require hospitalization during acute COVID-19.
"COVID can lead to long-term neurologic consequences," Al-Aly told 鶹ý. "The virus is not always as benign as some people think it is."
"It is not only brain fog," he emphasized. "There is clearly an increased risk of strokes, headaches, seizures, peripheral neuropathy, and more."
Using Veterans Affairs national healthcare databases, Al-Aly and co-authors built cohorts that included 154,068 individuals diagnosed with COVID-19 from March 2020 to January 2021, 5,638,795 contemporary controls who were not infected, and 5,859,621 historical controls from 2017.
The mean age of the COVID cohort was 61, and 89% were men. The researchers used inverse probability weighting to balance the cohorts. In the COVID group, they evaluated incident occurrences of 44 brain and other neurologic disorders about 1 year after acute SARS-CoV-2 infection. Both hospitalized and non-hospitalized COVID patients were included.
Compared with controls, COVID patients were 80% more likely to have a new occurrence of epilepsy or seizures, 43% more likely to develop mental health disorders such as anxiety or depression, 42% more likely to be diagnosed with movement disorders, and 35% more likely to have mild to severe headaches at 1 year. They also were 50% more likely to have an ischemic stroke.
People with COVID had a 77% higher risk of memory problems as those in the control groups. In some patients, post-COVID memory problems have resolved over time, Al-Aly noted.
COVID patients also had an increased risk of an Alzheimer's disease diagnosis compared with their counterparts who weren't infected (HR 2.03, 95% CI 1.79-2.31).
"It's unlikely that someone who has had COVID-19 will just get Alzheimer's out of the blue," Al-Aly said in a statement. "Alzheimer's takes years to manifest."
"But what we suspect is happening is that people who have a predisposition to Alzheimer's may be pushed over the edge by COVID, meaning they're on a faster track to develop the disease," he added. "It's rare, but concerning."
Analyses by age as a continuous variable revealed two key findings, the researchers noted. "Regardless of age and across the age spectrum, people with COVID-19 had a higher risk of all the neurologic outcomes examined in this analysis," they observed.
In addition, "our interaction analyses suggest that the effect of COVID-19 on risk of memory and cognitive disorders, sensory disorders and other neurologic disorders (including Guillain-Barré syndrome and encephalitis or encephalopathy) is stronger in younger adults," they pointed out. "The effects of these disorders on younger lives are profound and cannot be overstated; urgent attention is needed to better understand these long-term effects and the means to mitigate them."
Limitations to the study included a cohort of mostly white males. Few people were vaccinated for COVID because vaccines were not widely available during the study period. Other research led by Al-Aly has shown that vaccines the risk of neurologic complications from COVID-19.
The study also predated Delta and Omicron variants.
Disclosures
This research was funded by the U.S. Department of Veterans Affairs, the American Society of Nephrology, and Kidney Cure.
The researchers declared no competing interests.
Primary Source
Nature Medicine
Xu E, et al "Long-term neurologic outcomes of COVID-19" Nat Med 2022; DOI: 10.1038/s41591-022-02001-z.