Multiple Surgeries Linked to Cognitive Decline in Older Adults

A University of Sydney study has discovered that having several operations may cause cognitive decline. The study analyzed data from the UK’s Biobank to examine half a million people between the ages of 40 and 69, tracking their progress over a 20-year period through brain scans, cognitive tests, and medical records.

Many families have tales of how frequent hospital stays and surgeries deteriorated elderly relatives’ memory and reaction times. According to a recent study done by the University of Sydney, elderly patients‘ memory, reaction time, task switching, and problem-solving abilities are marginally affected by each successive surgery.

The study also discovered that brain MRIs of patients who had surgery revealed anatomical variations in memory-related brain regions.

This is the first study of its kind to look at how several complicated procedures affect brain health in a broad population utilizing brain imaging methods like MRIs.

The multinational team looked at data from nearly 500,000 persons in the UK between the ages of 40 and 69 who had surgeries, from day surgery to heart bypass operations, excluding neurosurgery and diagnostic procedures.

Patients then had cognitive function tests and brain MRIs as part of the study to check for indications of neurodegeneration.

According to the study, patients’ overall reaction times decreased by approximately 0.3 milliseconds for every additional procedure. With every additional surgery, cognitive flexibility, problem-solving skills, and memory for numbers and visuals all declined.

The part of the brain responsible for memory and learning, the hippocampus, was also shown to be smaller in people who had surgery. When compared to those who did not have multiple procedures, they also showed greater evidence of brain damage linked to blocked blood veins.

“The results suggest that the cognitive decline per surgery may seem small, but those changes and losses in neurodegeneration really start to add up after multiple surgeries,” says lead researcher Dr. Jennifer Taylor from the University of Sydney’s Faculty of Medicine and Health.

“We found that surgeries are safe on average but also that the burden of multiple surgeries on the brain health of older patients should not be underestimated.”

“This is a reminder to medical professionals to consider all treatment options and be cautious in recommending major surgery for older and more vulnerable patients. If surgery is the best or only treatment option, patients should be reassured that the cognitive harm from each surgery is small on average. Nonetheless, careful attention in perioperative care is required to prioritize brain health and recovery.”

Using a sizable population-based sample of British individuals from UK Biobank between 2006 and 2023, the researchers looked at the effect of surgical and medical hospital admissions on cognition. Their findings were published in The Lancet Healthy Longevity.

The largest repository of health data for study in the world, UK Biobank houses an enormous and constantly expanding dataset of biological, health, and lifestyle data gathered over 15 years from half a million UK volunteers.

A total of 46,706 individuals had their detailed magnetic resonance imaging (MRI) and detailed cognitive assessments combined.

Participants answered a series of questions in language and math to gauge their reaction times, recall, and flexibility of thought.

The same research team that discovered major surgery (such as heart, thoracic, vascular, and brain procedures) and hospital admissions are linked to cognitive impairment in elderly individuals is continuing their work with this study.

Future study, according to the experts, should concentrate on comprehending the biochemical underpinnings of neurodegeneration. Understanding how inflammation causes brain injury will be a crucial next step in determining whether delayed cognitive recovery following surgery is due to inflammation, as suggested by one theory.

For more information: Association between surgical admissions, cognition, and neurodegeneration in older people: a population-based study from the UK Biobank, The Lancet Healthy Longevity, https://dx.doi.org/10.1016/j.lanhl.2024.07.006