Anaesthetics could trigger Alzheimer's, say researchers

[Worcester]

Some anaesthetics could trigger the beginning of Alzheimer's disease, experts have warned.

Dr Pravat Mandal of the University of Pittsburgh Medical School, Pennsylvania, USA, and colleagues explain that anecdotal evidence on the link between surgery and cognitive problems dates back to the 1950s, but is still unclear.

Anaesthetics such as halothane are identified by Dr Mandal as potentially harmful to the brain.

The researchers say that recent test tube and animal experiments support the theory that certain anaesthetics can reduce the rate at which brain cells are born and develop. This could influence memory function.

Another possibility is that anaesthetics affect the pattern of beta amyloid proteins - potentially binding together to form the clumps or "plaques" which are a main cause of Alzheimer's disease.

"It has been reported that exposure to trace amounts of anaesthetic agents such as nitrous oxide, halothane and enflurane causes decline in performance in psychological tests," the researchers state.

Their findings suggests that exposure to halothane, isoflurane, and propofol can encourage clumping of beta amyloid protein.

Dr Mandal has identified specific sites where the general anaesthetic halothane interacts with beta amyloid protein.

He said that just six hours of exposure to halothane, commonly used in Asia and Africa, is sufficient to trigger protein clumping similar to that seen in people with Alzheimer's.

"It is a seriously deadly combination when an older person receives halothane," said Dr Mandal.

The team presented their findings at last week's annual meeting of the Society for Neuroscience in Atlanta, Georgia, USA.

"The main focus should now be using an anaesthetic that does not have any undesirable and deadly effects," they concluded.