According the team, by catching Alzheimer's disease before symptoms are apparent, doctors can prescribe treatments to slow down disease progression.
In the first study, Christos Davatzikos, PhD, Professor of Radiology at the University of Pennsylvania School of Medicine, Susan Resnick, PhD, of the National Institute on Aging and colleagues found brain deterioration in elderly adults who were classified as cognitively normal.
They used a highly accurate measurement tool, based on MRI images from the brains of people with Alzheimer's disease, to look at the MRI images of normal elderly and identify any remarkable structural changes.
By comparing these images, researchers were able to identify subtle structural changes in the brain tissue of healthy elderly with no noticeable symptoms of Alzheimer's disease.
"With the development of this technique, we hope clinicians will be able to detect structural brain changes that are typical of Alzheimer's disease earlier, before individuals present cognitive decline, by measuring levels of brain deterioration," Dr. Davatzikos said.
"We plan to integrate MRI with other biomarkers and especially with imaging of amyloid plaques, the protein deposits in the brain associated with Alzheimer's disease," Dr. Davatzikos added.
Results of the study demonstrated that significant brain deterioration was evident in a number of individuals who had no apparent symptoms when compared to cognitively healthy elderly; an increase of changes or abnormalities in brain structure was accompanied by a decrease in cognitive performance and there was an increase in Alzheimer's-like brain deterioration as people aged.
In the second study, Dr. Leslie Shaw, Professor of Pathology and Lab Medicine and Director of the Penn ADNI Biomarker Core Laboratory, and colleagues found they could predict when patients with mild cognitive impairment may convert to Alzheimer's disease by measuring significant cellular signatures.
They determined benchmark concentration levels of certain biological indicators in three populations: elderly who were cognitively normal, mildly cognitively impaired and had Alzheimer's disease.
Examining cerebral spinal fluid (CSF) samples collected from more than 50 study sites, they determined baseline levels of three proteins associated with Alzheimer's disease (total tau, P-Tau181P, and ß-Amyloid1-42).
What they found were significant differences in the level of these biomarker concentrations between groups.
"Analyzing changes in these CSF biomarker levels in people with mild cognitive impairment can detect the conversion to Alzheimer's disease, especially when used in conjunction with neuroimaging and psychological tests," Dr. Shaw said.
"By defining significant differences in biomarkers, we are able to accelerate our drug development efforts to look for compounds that modify these discrepancies and may treat Alzheimer's disease," Dr. Shaw added.
The studies were presented this week at the 2008 Alzheimer's Association International Conference on Alzheimer's Disease.