Brain measurements prove more accurate in predicting mild cognitive impairment

Researchers at the University of Oklahoma recently published a study showing that several measures of the brain, including blood flow and the brain’s ability to compensate for the lack thereof, are better predictors of mild cognitive impairment than risk factors such as high blood pressure and high blood pressure. cholesterol.

The findings advance the prospects of preventing memory problems early or treating them before they progress to dementia. The need is only increasing: approximately 18% of the world’s population has mild cognitive impairment, and 10-15% will develop dementia. By 2050, dementia is expected to affect 152 million people.

The research was led by a multidisciplinary group of researchers from the OU College of Medicine and published in Alzheimer’s and dementiaa journal of the Alzheimer’s Association. Their research focused on the brain’s vascular system – the network of blood vessels – and how it works differently in older adults with mild cognitive impairment.

People with mild cognitive impairment are at greatest risk for the next step, dementia. We are trying to decipher the ‘fingerprints’ of mild cognitive impairment – ​​what happens to the brain as someone progresses from healthy aging to mild cognitive impairment, and is there anything we can do to intervene and prevent the decline into dementia?”

Calin Prodan, MD, professor of neurology, OU College of Medicine and co-author of the article

The research team conducted different types of brain measurements on people at three stages of life: young adults, older adults with aging but healthy brains, and older adults with mild cognitive impairment. Each group played a short memory challenge game on a computer while wearing what looked like a swim cap with light sensors; The technology, called functional near-infrared spectroscopy, measured blood flow in the brain as participants were challenged to remember increasingly large strings of letters.

In the brains of young adults, blood flow increased, giving their brains the energy they needed to meet the demands of the game, a process called neurovascular coupling. In people with healthy aging brains, blood flow didn’t increase as much, but to compensate, their brains turned on other brain areas to help with the challenge, a process known as functional connectivity. In the brains of older adults with mild cognitive impairment, blood flow was greatly reduced and they lost the ability to compensate by recruiting other parts of the brain to help.

“People with mild cognitive impairment have lost that compensatory mechanism. There is a dramatic change in brain activity in people with mild cognitive impairment,” said Cameron Owens, Ph.D., lead author of the study. After earning his doctorate, Owens is now in his third year of medical school as part of the MD/Ph.D. course.

Another type of assessment – ​​a liquid biopsy – gave researchers an additional look at the brains of people with cognitive disabilities. This blood analysis measured the amount of cerebrovascular endothelial extracellular vesicles, or CEEVs, which are small particles released from the cells that line the brain’s blood vessels. Existing research shows that when the inner lining of blood vessels is damaged, it secretes CEEVS. People with mild cognitive impairment had more CEEVs in their brains than people with healthy aging brains. Additionally, MRI images confirmed that people with higher levels of CEEVs also had more ischemic damage, meaning the small blood vessels in their brains did not receive enough blood supply. The researchers believe this is the first time CEEVs have been measured in a cognitive state.

“Every brain is different, and there may be different reasons for cognitive impairment, but having these predictors – measuring neurovascular coupling, functional connectivity and CEEVs – potentially opens up opportunities to develop individualized interventions, whether it be pharmacological therapy or is non-invasive brain stimulation. or something as simple as cognitive behavioral therapy,” said Andriy Yabluchanskiy, Ph.D., associate professor of neurosurgery at the OU College of Medicine and co-author of the study.

The research will continue with several additional perspectives. The team plans to further analyze CEEVs, which resemble bubbles that carry a variety of materials, to see if that payload also contributes to mild cognitive impairment. In addition, because the study began during the COVID-19 pandemic, researchers are evaluating whether infection with the virus accelerated the progression to dementia in people with mild cognitive impairment.

“We are in the second year of a four-year study,” Yabluchanskiy said. “This is a prospective study in which all of our participants live here in Oklahoma.”