Brain Scans May Predict Alzheimer's

Test Using a Tracer Chemical May Show Which People With Memory Loss Will Get the Disease

Reviewed by Louise Chang, MD on May 07, 2007
From the WebMD Archives

May 7, 2007 -- A brain scan test may help predict which people with memory loss will develop Alzheimer's disease, a preliminary study shows.

Memory loss is a symptom of Alzheimer's disease. But most people with memory problems don't develop Alzheimer's.

Another hallmark of Alzheimer's disease is the buildup of plaque in the brain. That plaque, made of amyloid protein, has been found in brain autopsies of Alzheimer's patients.

The new study, published in Neurology, focuses on people with mild cognitive impairment, defined as memory loss that doesn't impair daily life and doesn't qualify for dementia diagnosis.

The study included 13 people in Finland with mild cognitive impairment. They were 70 years old, on average.

For comparison, the study also included 14 older Finnish adults (average age: 65) without memory problems.

Participants got an infusion of a tracer chemical called PIB, which binds to amyloid protein.

The researchers -- who included Juha Rinne, MD, PhD, of Finland's University of Turku -- used positron emission tomography (PET) brain scans to watch participants' brains absorb PIB.

Brain Scan Test

The brains of the patient group with memory loss tended to absorb more PIB than the comparison group without memory loss.

"This pattern of increased PIB in patients with [mild cognitive impairment] resembles what's seen in Alzheimer's disease and is suggestive of an early Alzheimer's disease process," Rinne says in an American Academy of Neurology news release.

But Rinne's team didn't follow the participants over time, so it's not clear if any of them developed Alzheimer's disease.

Larger, longer studies are needed to learn whether the PIB test predicts Alzheimer's disease in people with mild cognitive impairment, note the researchers.

The journal notes that Rinne has a consultancy agreement with a branch of GE Health Care, which makes PIB.

WebMD Health News


SOURCES: Kemppainen, N. Neurology, May 8, 2007; vol 68: pp 1603-1606. News release, American Academy of Neurology.

© 2007 WebMD, Inc. All rights reserved.