Here’s a shocking revelation: Boosting blood flow to the brain by clearing clogged neck arteries might not sharpen your thinking after all. But here’s where it gets controversial—despite what many have assumed, new research suggests that procedures like plaque removal or stenting in the carotid artery don’t outperform medications and lifestyle changes when it comes to improving cognitive skills. And this is the part most people miss: even patients with the lowest cognitive function at the start of treatment didn’t show significant improvement after these interventions.
In a groundbreaking substudy of the CREST-2 trial, involving over 2,000 adults with asymptomatic carotid artery blockage, researchers found no cognitive benefits from surgical procedures compared to medical management alone. The study, presented at the American Stroke Association’s International Stroke Conference 2026, challenges the long-held belief that restoring blood flow to the brain could enhance memory, attention, and decision-making. But why does this matter? Because carotid artery stenosis, often caused by plaque buildup, has been linked to cognitive decline, and many assumed fixing the blockage would fix the problem.
Lead researcher Ronald M. Lazar, Ph.D., FAHA, explains, ‘The brain relies on a steady blood supply for oxygen, and when that’s disrupted, neurons struggle, leading to cognitive issues.’ However, the CREST-2 substudy reveals that simply unclogging the artery isn’t enough to reverse these changes. Even more surprising? Cognitive decline was only evident in participants who had a stroke during the study, suggesting that the tests accurately detected neurological changes—just not from the treatments themselves.
Here’s the bold question: If restoring blood flow doesn’t improve cognition, what’s the real driver of cognitive decline in carotid artery disease? Could it be inflammation, neurodegeneration, or small vessel disease? Lazar hints at a fascinating counterpoint: ‘Small particles from blockages might travel to the brain over time, subtly impairing its function.’ This opens the door to entirely new areas of research.
These findings could reshape how doctors discuss treatment options with patients. While stenting or surgery remains crucial for stroke prevention, claiming cognitive benefits is no longer supported by evidence. However, if a patient’s cognitive skills worsen over time, it might signal the need to re-evaluate their treatment plan.
The study isn’t without limitations. Cognitive tests were conducted over the phone, skipping assessments of visuo-spatial skills and complex decision-making. Plus, the results may not apply to non-English-speaking populations. Still, the implications are profound. As Mitchell Elkind, M.D., FAHA, notes, ‘Cognitive decline is complex, and fixing large vessels might not address other pathways like inflammation or small vessel disease.’
Now, we want to hear from you: Do these findings challenge your understanding of brain health? Could this shift how we approach cognitive decline in vascular disease? Share your thoughts in the comments—let’s spark a conversation!
