Up to three million people over the age of 65 can receive "silent strokes" after surgery every year, according to research published in the Lancet medical journal.
Hidden strokes, which are not obvious except for brain scans, are more common than strokes that quickly cause visible symptoms, Canadian researchers have found.
They found that one in 14 patients received a silent stroke after surgery when they examined more than 1,000 people in the Americas, Asia, New Zealand and Europe.
This suggests that up to three million people over the age of 65 could experience silent strokes worldwide each year, according to a study led by the Hamilton Institute of Public Health Research and McMaster University in Hamilton, Ontario, Canada. .
Dr PJ Devereaux, principal investigator of the NeuroVISION study, said: "We found that" silent "covert strokes were actually more common than overt strokes in people 65 or older who had surgery."
Those who have had a silent stroke after surgery are 13% more likely to experience a cognitive decline, delirium, blast stroke or "mini stroke" caused by a temporary interruption of the blood supply to a part of the brain within one year.
Dr. Brian Rowe, Research Director at the Institute of Blood and Respiratory Health, Canadian Institutes of Health (CIHR), said: The NeuroVISION study provides important insights into the development of vascular trauma after surgery and adds to the motivating evidence of the importance of vascular health for cognitive decline.
Australian Associated Press