Brain Scans May Predict Alzheimer's
Test Using a Tracer Chemical May Show Which People With Memory Loss Will Get the Disease
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
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
The journal notes that Rinne has a consultancy agreement with a branch of GE
Health Care, which makes PIB.