Multiple Surgeries Linked to Cognitive Decline in Older Adults

A study led by the University of Sydney has uncovered that undergoing multiple surgeries may contribute to cognitive decline in older adults. This finding comes from an analysis of data from the UK Biobank, encompassing half a million patients aged between 40 to 69 over a span of 20 years. The study explored brain imaging, cognitive function tests, and medical records to assess the impact of surgeries on memory, reaction time, and brain health.

Key Findings on Surgeries and Cognitive Decline

The study found that multiple surgeries are associated with a small but measurable impact on cognitive function and brain structure in older patients.

Cognitive Impacts

• Memory & Reaction Time: Reaction times slowed by an average of 0.3 milliseconds per additional surgery.
• Cognitive Flexibility & Problem Solving: Declines in task-switching ability and capacity for remembering pictures and numbers were observed.
• Brain Changes in the Hippocampus: MRIs showed smaller hippocampi and evidence of brain damage linked to blocked blood vessels in patients with multiple surgeries.

"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," said Dr. Jennifer Taylor, lead researcher at the University of Sydney's Faculty of Medicine and Health.

Clinical Implications and Recommendations

The findings suggest that while surgeries are generally safe for older patients, the cumulative effect of multiple surgeries on brain health should not be overlooked.

"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," Dr. Taylor advises.
"Careful attention in perioperative care is required to prioritize brain health and recovery."

Methodology and Study Population

The study, published in The Lancet Healthy Longevity, leveraged the extensive UK Biobank data from 2006–2023. The UK Biobank provides a comprehensive source of health data, with half a million UK volunteers contributing to a wide range of biological, health, and lifestyle information.

• Participants: 46,706 adults underwent detailed MRIs and cognitive function testing.
• Cognitive Tests: Participants were tested on reaction time, memory, and flexibility of thinking through language and math problems.
• Surgery Types Included: Surgeries ranged from minor day surgeries to major operations like heart bypasses, excluding diagnostic and neurosurgical procedures.

Future Directions and Research

The study builds on prior work from the research team, which found that major surgeries and hospital admissions are linked to cognitive decline. The researchers propose that further studies are needed to explore the biological mechanisms behind these findings. One hypothesis is that inflammation could play a significant role in delayed cognitive recovery post-surgery.

"This paper represents a critical milestone for our field," says Professor Robert Sanders.
"We are already testing potential therapeutics in clinical trials as we strive to advance safe anesthesia and perioperative care."

Reference

Journal Information: The Lancet Healthy Longevity
Provided by: University of Sydney