Skip to main content

Major surgery associated with small, long term decline in brain functioning

Major surgery is associated with a small long-term decline in cognitive functioning -- equivalent, on average, to less than five months of natural brain ageing, finds a study in The BMJ today.
But the odds of substantial cognitive decline also increase after surgery -- approximately doubling -- although the likelihood of this is much lower than after admission to hospital for a medical condition, the findings show.
Cognitive decline is the gradual loss of brain functioning that occurs with ageing. It often starts decades before the conventional definition of old age and accelerates with ageing and the presence of an increasing number of underlying health conditions.
Certain health issues, such as stroke, can lead to a large "step change" in cognitive decline, and there have been concerns that surgery might also do this, with some patients refusing beneficial surgical procedures as a result, say the researchers.
Few previous studies have looked at the potential impact of major surgery on cognitive decline and most of them have relied on a single preoperative assessment of cognitive functioning rather than tracking cognitive decline over time.
To address this, the researchers accessed data on 7,532 British civil servants enrolled in the Whitehall II Study, which has been looking at the impact of social, behavioural, and biological factors on long term health.
All the patients were aged between 35 and 55 in 1985 and received up to five cognitive assessments over a 19-year period (1997 to 2016).
Any hospital admissions requiring at least a two-night stay were identified in hospital episode statistics. Overall, 8,982 "major" events were identified: 4,525 operations; 4,306 medical admissions; and 151 strokes.
Among the 7532 participants, 4954 weren't admitted to hospital for major surgery, but 1250 were: 613 for a medical condition and 715 for both reasons.
After accounting for age-related cognitive decline, the authors calculated that major surgery was associated with a small additional cognitive decline of less than five months (0.35 years), on average.
Admissions for medical conditions and stroke were associated with a far greater additional cognitive decline of 1.4 and 13 years, respectively.
Hospital admission for major surgery or a medical condition also increased the odds of substantial cognitive decline by 2.3 and 6.2, respectively.
Substantial cognitive decline occurred in 5.5% of patients who spent time in hospital for a surgical procedure and 12.7% of those treated in hospital for a medical condition, compared with 2.5% of people who had no major hospital admissions.
This is an observational study, so no firm conclusions can be drawn about cause and effect, and hospital admissions likely act as a surrogate measure for ill health, the researchers point out. What's more, no information on the type of anaesthesia used was available, so its potential role in any long-term cognitive change couldn't be assessed.
Nevertheless, the researchers conclude: "Overall our data suggest that major surgery is associated with a small long term mean change in the age-related cognitive trajectory, with the odds of substantial decline doubling."
While they emphasise that the impact of surgery on cognition is lower than for medical admissions, this needs to be explained to patients, they say. "This information should be conveyed to patients and be weighed against the potential health and quality of life benefits of surgery during informed consent."
Researchers in a linked editorial say, "This study is reassuring in that the authors found no large declines in cognition after surgery." But as cognition deteriorates towards the end of life and contact with health services increases during this time, further exploration into mortality is key, they add.
"Importantly, we need to know which risk factors are modifiable and which are not. If some of [the] findings (particularly those linked to non-surgical admissions) are closely related to dying it might be challenging to disentangle the preventable from the inevitable."
They conclude: "Although the Whitehall study cannot reflect the UK's population, estimates obtained from this cohort reinforce the need for action to shift population risk profiles for cognitive decline [...] across the life course."
Story Source:
Materials provided by BMJ. 
Note: Content may be edited.

Comments

Post a Comment

Popular posts from this blog

Dark matter may be older than the Big Bang

Dark matter, which researchers believe make up about 80% of the universe's mass, is one of the most elusive mysteries in modern physics. What exactly it is and how it came to be is a mystery, but a new Johns Hopkins University study now suggests that dark matter may have existed before the Big Bang. The study, published August 7 in  Physical Review Letters , presents a new idea of how dark matter was born and how to identify it with astronomical observations. "The study revealed a new connection between particle physics and astronomy. If dark matter consists of new particles that were born before the Big Bang, they affect the way galaxies are distributed in the sky in a unique way. This connection may be used to reveal their identity and make conclusions about the times before the Big Bang too," says Tommi Tenkanen, a postdoctoral fellow in Physics and Astronomy at the Johns Hopkins University and the study's author. While not much is known about its origins,...
Post a Comment
Read more

All of the starlight ever produced by the observable universe measured

All of the starlight ever produced by the observable universe measured The team's measurement, collected from Fermi data, has never been done before. This map of the entire sky shows the location of 739 blazars used in the Fermi Gamma-ray Space Telescope’s measurement of the extragalactic background light (EBL). The background shows the sky as it appears in gamma rays with energies above 10 billion electron volts, constructed from nine years of observations by Fermi’s Large Area Telescope. The plane of our Milky Way galaxy runs along the middle of the plot. From their laboratories on a rocky planet dwarfed by the vastness of space, Clemson University scientists have managed to measure all of the starlight ever produced throughout the history of the observable universe. Astrophysicists believe that our universe, which is about 13.7 billion years old, began forming the first stars when it was a few hundred million years old. Since then, the universe has become a st...
Post a Comment
Read more

Reflecting antiferromagnetic arrangements

Reflecting antiferromagnetic arrangements : Brookhaven Lab physicists Claudio Mazzoli (left) and Mark Dean at the Coherent Soft X-ray Scattering (CSX) beamline at the National Synchrotron Light Source II. Mazzoli and Dean are part of the team of scientists led by Rutgers University that used the CSX beamline to image some magnetic domains in an iron-based 'antiferromagnetic' material. The ability to image these domains is key to developing spintronics, or spin electronics, for practical applications. A team led by Rutgers University and including scientists from the U.S. Department of Energy's (DOE) Brookhaven National Laboratory has demonstrated an x-ray imaging technique that could enable the development of smaller, faster, and more robust electronics. Described in a paper published on Nov. 27 in  Nature Communications , the technique addresses a primary limitation in the emerging research field of "spintronics," or spin electronics, using magneti...
Post a Comment
Read more