DENVER, Colo. — COVID-19 can lead to many lingering ailments weeks and even months after infection. Now, a disturbing new study suggests Alzheimer’s disease may be among them. Researchers with the Alzheimer’s Association say coronavirus may trigger Alzheimer’s, accelerating the onset of the most common form of dementia.
Study authors discovered that memory loss and confusion was common among hundreds of older COVID patients six months after their infection. The symptoms had a link to biological markers of brain injury, inflammation, and dementia.
The study finds those suffering cognitive decline after infection were prone to low blood oxygen, which can lead to the devastating neurological illness. Scientists add patients experienced this after brief exertion and were in poor overall physical condition.
“We’re starting to see clear connections between COVID-19 and problems with cognition months after infection,” says Dr. Gabriel de Erausquin from the University of Texas in a media release.
“It’s imperative we continue to study this population, and others around the world, for a longer period of time to further understand the long-term neurological impacts of COVID-19.”
Long COVID may lead to cognitive decline
The results come from a study of almost 300 Argentinians with coronavirus who researchers tracked for three to six months. More than half displayed persistent forgetfulness. A quarter had additional cognition problems such as loss of speech and executive thinking skills.
The team believes these issues resulted from ongoing smell dysfunction starting after the original COVID infection. The findings sheds light on short and long-term neuropsychiatric symptoms doctors have been seeing in patients during the pandemic. These “long COVID” symptoms include the loss of smell or taste and mental deficits with thinking and attention, typically called “brain fog.”
“These new data point to disturbing trends showing COVID-19 infections leading to lasting cognitive impairment and even Alzheimer’s symptoms,” says Dr. Heather Snyder, the vice president of medical and scientific relations at the Alzheimer’s Association.
“With more than 190 million cases and nearly 4 million deaths worldwide, COVID-19 has devastated the entire world. It is imperative that we continue to study what this virus is doing to our bodies and brains. The Alzheimer’s Association and its partners are leading, but more research is needed.”
A second study of 32 people hospitalized with mild to moderate COVID symptoms also discovered more than half of these individuals suffered from cognitive decline. Multiple cognitive impairments and short-term memory loss were among the most common symptoms. Researchers linked lower thinking scores to lower levels of oxygen during a six-minute walk test. Doctors use this assessment to examine cardiopulmonary disease patients.
“A brain deprived of oxygen is not healthy, and persistent deprivation may very well contribute to cognitive difficulties,” explains lead author Dr. George Vavougios from the University of Thessaly.
“These data suggest some common biological mechanisms between COVID-19’s dyscognitive spectrum and post-COVID-19 fatigue that have been anecdotally reported over the last several months.”
Alzheimer’s substances increasing in COVID patients
Another study of 310 older COVID patients in the U.S. — who were cognitively normal prior to their illness — discovered higher levels of tau proteins in their brains. The rogue protein is one of the key indicators in Alzheimer’s development. As these proteins build up, they form angles which block off and kill neurons. Study authors took blood samples from these participants, which revealed that half were also suffering from confusion.
“These findings suggest that patients who had COVID-19 may have an acceleration of Alzheimer’s-related symptoms and pathology,” concludes lead author Prof. Thomas Wisniewski from New York University. “However, more longitudinal research is needed to study how these biomarkers impact cognition in individuals who had COVID-19 in the long term.”
Researchers presents all three studies at the virtual Alzheimer’s Association International Conference in Denver.
South West News Service writer Mark Waghorn contributed to this report.