Brain watchers track progress of Alzheimer's

Medical researchers say they are beginning to observe Alzheimer's disease as it progresses by producing some of the first pictures of the physical changes that take place in the living brain.

In five studies released this week, scientists have reported on new kinds of medical imaging tests that can spot defects in the brain and track the illness as it advances. The techniques also can detect the brain's reaction to treatment, suggesting new ways to speed the discovery of therapies.

"We are beginning to measure changes in the biology of the disease, instead of asking people questions to try to ascertain the quality of their memory," says William Thies, of the Chicago- based Alzheimer's Association.

A century after the memory-robbing disease was first identified, an international science meeting in Madrid has been told of advances that may thaw the glacial pace of innovation. The ailment, which afflicts 28 million people worldwide, still can only be diagnosed with certainty with an autopsy, when pathologists physically examine the brain.

By seeing brain damage in images projected on to a computer screen, scientists say they may revolutionise research, diagnosis and treatment. Alzheimer's disease robs the brain of its memory and processing skills. And the number of victims is expected to grow fourfold by the middle of the century as populations age and baby boomers reach retirement.

Studies at the 10th International Conference on Alzheimer's Disease and Related Disease in Madrid also explore connections to diabetes and heart disease, as well as the effectiveness of some current medicines.

Researchers from the Karolinska Institute in Stockholm presented a study of more than 1100 people linking Alzheimer's to people with slightly higher than normal sugar levels. Scientists since 2004 have linked type 2 diabetes with Alzheimer's and the Karolinska study, done over nine years, says the link may take hold early. This is a key finding since research suggests diabetes is under-reported and growing.

"This is the time to move forward and not wait for the inundation of baby boomers to overwhelm our health-care system," says John Morris, director of the Alzheimer Disease Research Center at Washington University School of Medicine in St. Louis.

The condition is so complex, and the brain so difficult to manipulate, that doctors still have few options for their patients, researchers say. Existing drugs such as Aricept, Razadyne and Exelon ease symptoms without slowing Alzheimer's inexorable advance.

The new studies reflect researchers' efforts to use lasers and MRI and PET scanning machines to uncover brain health in much the same way that cholesterol and blood pressure tests can be used to predict and prevent heart disease.

Using the scans may allow researchers to more quickly see if experimental drugs are having a biological effect, thereby reducing the number of patients needed in studies and research costs.

"The hope is, by developing these kinds of biological markers we'll be able to make these clinical trials more efficient and effective, and we'll be able to look at more drugs," says Neil Buckholtz, a US National Institute on Aging official.

"There's a lot of science pointing to the future that will help us identify the disease early, maybe even before it becomes symptomatic," says the Alzheimer's Association's Dr Thies.

In one study, researchers from the Mayo Clinic in Rochester, Minnesota, are using MRIs to see if behavioural changes in patients taking Pfizer's Aricept can be identified in brain scans.

PET scans are being used at the University of California at Los Angeles and the University of Pittsburgh to track chemicals that latch on to amyloid plaque, clumps of protein that collect in the brain and whose presence leads to a definitive diagnosis of Alzheimer's in an autopsy. It may be possible to use scans to determine if someone has mild impairment or a more serious condition.

"It would be great to detect the disease early, but it will be terrible if we don't have anything to offer the patient," says Professor Morris.

The first company that can crack the puzzle presented by Alzheimer's disease will reap huge financial rewards, says Dr Thies. Currently, 42 drugs are in development for Alzheimer's, according to the Pharmaceutical Research and Manufacturers of America.

"It's one of the last great paydays for the pharmaceutical industry," Dr Thies says.

- BLOOMBERG