Researchers are trying to unravel why some COVID-19 survivors suffer “brain fog” and other problems that can last for months, and new findings suggest some worrisome overlaps with Alzheimer's disease.
Research with a group of older adults in Argentina found a significant amount of dementia-like changes in memory and thinking for at least six months after a suffering from COVID-19, no matter the severity of their infection. Another study found Alzheimer's-related proteins in the blood of New Yorkers whose COVID-19 triggered brain symptoms early on.
The Times of Israel's recent article entitled “Scientists try to understand COVID ‘brain fog,' potential link to Alzheimer's” reports that the preliminary findings were reported at an Alzheimer's Association meeting last week. Experts say that much more research is needed (and has started) to determine whether COVID-19 might raise the risk of Alzheimer's or other brain problems later in life, or if people subsequently recover.
“If you did have COVID, this does not necessarily mean that you will be impacted,” said the Alzheimer's Association's Heather Snyder. Protecting the brain from COVID-19 offers one more reason to get vaccinated, she added.
Some hints about the risk were the result of a study that looked at 300 people in the Jujuy province of Argentina that kept a health registry of anyone tested for the virus—regardless of whether they had symptoms. Researchers reviewed the registry for people 60 and older who had no record of brain disorders prior to the pandemic and asked if they'd undergo cognitive testing.
“It's quite scary, if I have to put it bluntly,” said Dr. Gabriel de Erausquin of the University of Texas Health Science Center at San Antonio, who is leading the study.
Between three and six months after their coronavirus infection, about 20% of the older adults showed issues with their short-term memory. Moreover, 34% had a more substantial impairment including trouble finding words and difficulty with longer-term memory, what de Erausquin called a “dementia-like syndrome.” The severity of their COVID-19 didn't predict the problems. Rather, those most at risk had a persistent loss of smell, which is frequently temporary with COVID-19. But de Erausquin noted the brain's olfactory region is directly linked to areas critical for memory, and a loss of smell is sometimes an early sign of degenerative diseases such as Alzheimer's or Parkinson's.
The study will monitor the participants for three years and see how they fare. While the early findings focused on older adults, de Erausquin said there's other evidence that lingering problems in younger COVID-19 survivors tend to be with the ability to concentrate.
Previous research has shown that certain viruses may play a part in later Alzheimer's, and “the pandemic certainly gave us an unwelcome opportunity” to try to finally better understand why, Snyder said.
Reference: The Times of Israel (Aug. 3, 2021) “Scientists try to understand COVID ‘brain fog,' potential link to Alzheimer's”