MONDAY JULY 21, 2008 (foodconsumer.org) — A new study in the July 19 issue of The Lancet suggests that amyloid plaques in the brains of patients with Alzheimer’s disease may not be the cause of the disease.
The study showed that removal of amyloid plaques from the brain did not stop progression of Alzheimerâ€™s.
In the study, Dr. Clive Holmes from the Memory Assessment and Research Centre at Moorgreen Hospital in Southampton and colleagues looked at data on 80 Alzheimer’s patients who had received an experimental vaccine called AN1792.
Amyloid plaques are believed to cause Alzheimer’s disease, a major form of dementia. And removal of the plaques was expected to improve the condition.
The vaccine did reduce the number of plaques in the brains of patients, or even completely got rid of these plaques in some patients; Holmes was cited by Healthday.com as saying.
However, the researchers found no evidence that removing plaques at least by using vaccine made any difference in the clinical outcomes of the Alzheimer’s patients.
Dr. Holmes was cited as saying that plaques are not sufficient to account for the progression of this disease and a new approach would be needed to treat the disease.
Helathday.com cited Dr. Sam Gandy, chairman of the Alzheimer’s Association’s National Medical and Scientific Advisory Council as saying that the findings suggest whatever causes the plaque buildup affects the disease progression.
Alzheimer’s disease, which has no cure, affects an estimated 4.5 million Americans. The disease usually begins after age 60, and risk goes up with age, according to the National institute of Health.
Another study from Russia suggested that Alzheimer’s disease can be treated and the condition can be improved.
In the study, Dr. Rachelle S. Doody, professor of neurology at the Alzheimer’s disease and Memory Disorders Center at Baylor College of Medicine in Houston, and colleagues randomly assigned 20 milligrams of the drug dimebon, a drug approved in Russia as an antihistamine, or a placebo to 183 Russian patients with mild to moderate Alzheimer’s disease.
At six months, patients on dimebon experienced significant improvement in thinking abilities, behavioral symptoms and their daily skills compared to those receiving placebo.
The researchers found at six months, patients on dimebon had their condition improved by 1.9 points on the ADAS-cog scale while those on placebo experienced continued decline in the brain functions.
After one year, the drug dimebon resulted in an improvement of 6.9 points on the scale.
DAS-cog (Alzheimer’s Disease Assessment Scale – Cognitive) is the common clinical tool used to evaluate Alzheimer’s patients.
Dimebon is manufactured by the San Francisco-based pharmaceutical company Medivation, according to healthday.com.
A phase III trial also is being conducted in the United States, Europe and South America, Doody was cited as saying.