Anesthésie et altérations cérébrales

http://www.nature.com/news/2007/070312/full/070312-1.html

Commonly used anaesthetic alters mouse brains

Study adds to concerns over drug link to Alzheimer's.

Michael Hopkin

Breathe deep: inhaled anaesthetics can do funny things to mouse brains. Corbis

Exposure to widely used anaesthetic drugs increases production of a brain protein thought to cause Alzheimer's disease, a study of mice has shown. The research feeds concern that general anaesthesia may be linked to dementia in humans.

Inhaled doses of halothane, one of a class of drugs called volatile anaesthetics, increase the amount of a protein called amyloid beta in mouse brains, researchers at the University of Pennsylvania in Philadelphia have found.

Some 60 million people worldwide are given volatile anaesthetics each year. The drugs are known to cause 'post-operative cognitive decline' in many cases, which can last for days, weeks or years.

If these drugs boost production of amyloid beta, they may also be linked to long-term dementias such as Alzheimer's. The brains of Alzheimer's patients contain high levels of amyloid beta, although the molecule's links with disease are still unknown.

There are no data on whether the effect occurs in humans. Until such information is gathered, it will be difficult to say whether anaesthetists should stop using volatile anaesthetics, including halothane and the related isoflurane, the most widely used of the group.

Nevertheless, it adds to a growing pool of evidence that these drugs can damage the brain. "This creates a little more concern than before," says Roderic Eckenhoff, one of the researchers, who report the study in Neurobiology of Aging¹. "But if you need surgery you should get your surgery."