Researchers in there study are trying to observe why surgery may trigger cognitive problems in some people but studies are ongoing. It's long been known that some older people develop problems with memory and other mental functions after an operation - a condition known as Post Operative Cognitive Dysfunction (POCD).Often relatives will say that the person has 'never been the same' as they were before surgery. It was assumed, at first, that the anaesthetic was to blame. Research then showed that those who had cognitive problems had a fall in oxygen levels in the blood a few days after the surgery - but the reason for this is unclear.
The leading UK charity, Research into Ageing, has been helping fund a large international study into POCD and its causes. Results are to be published, but so far it looks as if surgery may be a major stressor for some people and maybe there is a genetic factor involved. Brain changes, similar to those that occur in dementia, have been found on anaesthetic exposure in animal studies. Further study into the genetic susceptibility of some people to anaesthetics is ongoing at the University of Leicester, UK.