Pet scans detect brain differences in people at risk for Alzheimer’s
Using brain imaging, researchers at Columbia University Medical Center (CUMC) have found clear differences in brain function between healthy people who carry a genetic risk factor for Alzheimers disease and those who lack the factor.
Because researchers believe that Alzheimers disease starts changing the brain years before any symptoms appear, the disease may be most amenable to treatment in these pre-clinical stages. If so, detecting the early changes will be crucial for future therapies.
People who carry the genetic risk factor, the å 4 allele of the Apolipoprotein (APOE) gene, have higher risk of developing the disease than non-carriers and usually show symptoms earlier. “It is possible that what were seeing in the APOE- å4 carriers are early changes in the brain caused by Alzheimers disease,” says the studys senior author, Yaakov Stern, Ph.D., of CUMCs Taub Institute and Sergievsky Center.
But he and the studys first author, Nikolaos Scarmeas, M.D., caution that more research is needed before its known for certain if the difference is an early sign of Alzheimers. “Its also possible that the brain differences we see are related to the APOE gene but are not necessarily directly related to incipient Alzheimers,” says Dr. Scarmeas, a neurologist in the Taub Institute, Sergievsky Center and neurology department. “Even so, the differences weve found may provide information on how the å4 allele predisposes carriers to Alzheimers disease.”
The present study appears in the Nov.-Dec. 2004 issue of the American Journal of Geriatric Psychiatry.
About the Study
The researchers looked at six people who carried the APOE- å4 risk factor and 26 non-carriers. None of the 32 participants, mostly in their 60s and 70s, had any signs of dementia or memory deficits and the two groups could not be distinguished from one another by standard cognitive tests.
PET scans taken while the subjects were performing a memory task, however, showed clear differences between the two groups. As the participants tried to remember if theyd seen a particular shape before, one pattern of brain activation appeared in the APOE- å4 carriers while a different pattern appeared in the non-carriers.
Dr. Scarmeas says the difference may indicate that APOE- å4 carriers have to compensate for early damage done by Alzheimers by switching to an alternate brain network to complete the task. It could also be that their different genetic makeup results in different patterns of brain activity.
In previous studies, Dr Scarmeas has demonstrated APOE-related changes in brain activity in patients that already have Alzheimers disease and in healthy, young, college-age people. Drs Scarmeas, Stern and a large group of other researchers at the Taub Institute are using advanced brain imaging techniques to examine changes in cognition and brain function as a result of normal aging and brain diseases, such as Alzheimers disease.
Media Contact
More Information:
http://www.columbia.eduAll latest news from the category: Health and Medicine
This subject area encompasses research and studies in the field of human medicine.
Among the wide-ranging list of topics covered here are anesthesiology, anatomy, surgery, human genetics, hygiene and environmental medicine, internal medicine, neurology, pharmacology, physiology, urology and dental medicine.
Newest articles
Lighting up the future
New multidisciplinary research from the University of St Andrews could lead to more efficient televisions, computer screens and lighting. Researchers at the Organic Semiconductor Centre in the School of Physics and…
Researchers crack sugarcane’s complex genetic code
Sweet success: Scientists created a highly accurate reference genome for one of the most important modern crops and found a rare example of how genes confer disease resistance in plants….
Evolution of the most powerful ocean current on Earth
The Antarctic Circumpolar Current plays an important part in global overturning circulation, the exchange of heat and CO2 between the ocean and atmosphere, and the stability of Antarctica’s ice sheets….