New research shows improving blood flow to the brain in arteries with plaque did not improve cognitive skills

 Why would you even think that? With the Circle of Willis being complete there are four arteries feeding the brain, a miniscule improvement in one artery won't bring more oxygen to the brain. 

Doesn't ANYONE IN STROKE KNOW HOW TO THINK?

Proving once again we have blithering idiots in stroke! I would never do stenting or a carotid endarterectomy because of the possible bad consequences (i.e. stroke).

New research shows improving blood flow to the brain in arteries with plaque did not improve cognitive skills

Improving blood flow to the brain by opening a narrowed neck artery may not improve patients’ cognitive skills, according to a preliminary late-breaking science presentation at the American Stroke Association’s International Stroke Conference 2026. 

“Whether patients undergo a procedure to remove plaque in the carotid artery, known as a carotid endarterectomy, stenting to insert a flexible tube to hold open the narrowed part of the artery, or a combination of medications and lifestyle guidance without a procedure, there should be no expectation that cognition will improve after the treatment,” said study lead author Ronald M. Lazar, Ph.D., a professor of neurology at the University of Alabama at Birmingham and director of the UAB Evelyn F. McKnight Brain Institute. 

Carotid artery stenosis is a condition where the major blood vessels in the neck become narrowed, usually because of plaque buildup. Standard treatment focuses on strong medical therapy — such as aspirin to prevent blood clots, medicines to control blood pressure and cholesterol, and lifestyle changes like quitting smoking, being more active, eating a healthy diet and losing weight when needed. When the artery becomes severely narrowed, or more than 70 percent blocked, doctors may also recommend a procedure to reopen it, either through carotid endarterectomy or stenting.

The CREST‑2 Trial (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis) compared how often strokes occurred in people who were randomly assigned to one of three groups: intensive medical therapy alone, medical therapy plus carotid endarterectomy or medical therapy plus stenting.

Earlier studies have generally shown that people with carotid stenosis tend to do worse on cognitive tests. To examine this more closely, CREST‑2 included a special “cognitive core” component. Participants completed cognitive testing before treatment and then once a year for up to four years. This was the first large randomized trial of carotid stenosis to include cognitive performance as a major outcome.

“The brain needs a steady flow of blood to get oxygen for its cells. When blood vessels can’t deliver enough blood, the brain doesn’t get enough oxygen, and the neurons can’t work properly, which impacts the brain’s ability to function properly. This often leads to changes in cognitive skills like attention, processing speed and decision-making skills,” Lazar said.

In 2021, Lazar and colleagues published results in Stroke, the journal of the American Stroke Association. They found that, before treatment, 786 patients in CREST‑2 with severe but symptom‑free carotid stenosis scored lower on cognitive tests — especially memory — compared with a separate group of people matched for age, sex and cardiovascular risk factors.

“The 2021 analysis indicated that revascularization might improve cognitive function,” said Lazar, who is the principal investigator of the Cognitive Core substudy and an overall co‑investigator for CREST‑2.

However, after an average of 2.8 years of follow‑up, the substudy found no meaningful differences in thinking or memory between people who had a procedure (stenting or surgery) and those who only received intensive medical therapy. “Even among participants with the lowest cognitive function at the start of the study, who were expected to gain the most from these treatments, there were still no differences in cognitive skills among the treatment groups,” Lazar said.

Participants who had a stroke during the study did show cognitive decline, confirming that the cognitive tests were sensitive enough to detect real changes in brain function.

These findings may influence how clinicians talk with patients about the potential benefits of surgery or stenting. 

“Health care professionals can no longer assert that treatment of carotid stenosis will improve cognition. However, worsening cognition over time may be a signal that treatment may need to be reevaluated and possibly adjusted,” Lazar said.

The study could not determine whether reduced blood flow alone explains cognitive decline in people with carotid artery disease. “Some characteristics of a blockage can cause small particles to travel to the brain. These particles may, over time, affect how the brain functions. This is an area we plan to explore in our future research,” Lazar said.

The study had limitations. All cognitive testing was done by phone, which meant researchers could not assess visuo‑spatial skills or the full range of executive functions like complex decision‑making. In addition, only English‑speaking participants were included, which means the results may not apply to people from other language or cultural backgrounds.

At UAB, Lazar holds the Evelyn F. McKnight Endowed Chair for Learning and Memory in Aging.