How surgery in old age raises risk of strokes

Undergoing surgery in old age raises the risk of “silent strokes” that hasten cognitive decline, scientists have warned.

A new study reveals that pensioners who have an operation have a one in 14 chance of suffering a silent or “covert” stroke – an event that shows no obvious symptoms but can damage the brain. More than 1,100 patients across the world were given Magnetic Resonance Imaging (MRI) scans nine days after some form of major non-cardiac surgery. They were then followed up a year later to assess their cognitive abilities. The researchers found that not only did having a silent stroke double the chances of cognitive decline a year on, it also increased the chances of a full life-threatening stroke.

Suffering a mini-stroke increased the risk of experiencing postoperative delirium as well.

Associate professor of medicine at University of Western Ontario, Dr. Marko Mrkobrada, said: “Surgeons are now able to operate on older and sicker patients thanks to improvements in surgical and anesthetic techniques.

“Despite the benefits of surgery, we also need to understand the risks.”

Published in the Lancet, the study highlights the crucial role played by the vascular system on brain health, its authors said.

Roughly one in 200 over people aged over 65 who have a major operation go on to suffer an “overt” stroke. A normal stroke, such as an ischemic stroke, is often identifiable by symptoms such as slurred speech, numbness, or loss of movement in the face or body. This is because the blood supply to parts of the brain which control those functions is cut off. However, a silent stroke is hard to recognise because it disrupts blood supply to parts of the brain that do not control any visible functions.

Dr. Brian Rowe said: “The NeuroVISION Study provides important insights into the development of vascular brain injury after surgery, and adds to the mounting evidence of the importance of vascular health on cognitive decline.

“The results of NeuroVISION are important and represent a meaningful discovery that will facilitate tackling the issue of cognitive decline after surgery.”