Anesthetics may Increase Risk of Alzheimer's Disease

Ivanhoe Newswire
Friday, October 27, 2006; 12:00 AM

By Vivian Richardson, Ivanhoe Health Correspondent

ORLANDO, Fla. (Ivanhoe Newswire) -- Could anesthetics used during surgeries trigger Alzheimer's disease in elderly patients? Several new test tube and animal studies raise the question.

Many of us know a loved one or relative who was not quite the same after having major surgery. Elderly men and women often report memory problems after going under anesthesia for an operation. Researcher Pravat Mandal, Ph.D., from the University of Pittsburgh Medical School wanted to find out why. "There was no clear mechanism how these anesthesia work, so that's what I wanted to investigate," Dr. Mandal told Ivanhoe.

In test tube experiments, Dr. Mandal tested several different type of anesthetics on beta amyloid protein. Clumps, or plaques, of this substance in the brain are thought to be a possible cause of Alzheimer's disease. Three anesthetics -- halothane, isoflurane, and propofol -- were found to encourage clumping of the protein, all at higher concentrations than are normally used in patients.

Whether or not this means use of these anesthetics on elderly patients is the cause of memory problems or would trigger Alzheimer's cannot be determined yet, Dr. Mandal said. He wants to conduct further testing on animals before he can draw any conclusions.

Halothane is an older anesthetic and is not commonly used in the United States or Europe but is used in some other countries because it is inexpensive. Studies have linked it to liver problems after repeated exposure. Dr. Mandal used nuclear magnetic resonance spectroscopy to show that halothane interacts with a specific location along the beta amyloid protein, encouraging other proteins to bind.

Use of isoflurane is also on the decline. However, the intravenous propofol, also called Diprivan, is commonly used today. In Dr. Mandal's test tube experiments, this anesthetic encouraged beta amyloid proteins to clump, although the effect was seen at concentrations higher than what's used for anesthesia.

This article was reported by Ivanhoe.com, who offers Medical Alerts by e-mail every day of the week. To subscribe, go to: http://www.ivanhoe.com/newsalert/.

SOURCE: Ivanhoe interview with Pravat Mandal, Ph.D., University of Pittsburgh School of Medicine