The study included 83 volunteers aged 49 to 84. Based on cognitive testing, 25 patients had Alzheimers disease, 28 had mild cognitive impairment and 30 were normal controls.
Researchers performed PET brain scans after intravenously injecting the volunteers with the new chemical marker called FDDNP, the molecule that binds to the plaque and tangle deposits found in Alzheimers disease.
Scientists found distinct differences among people with normal brain aging, patients with Alzheimers disease and people with mild cognitive impairment.
The PET imaging showed that the more advanced the disease the higher the FDDNP concentration in areas where the abnormal protein deposits typically accumulate in the temporal, parietal and frontal brain regions. Patients with Alzheimers disease showed the most FDDNP binding, indicating a higher level of plaques and tangles than other subjects.
"We could see the definitive patterns starting early in patients with mild cognitive impairment and advancing in those with Alzheimers disease," said Dr. Jorge Barrio, study author and professor of medical and molecular pharmacology, David Geffen School of Medicine at UCLA.
All subjects also received a PET brain scan using a more conventional chemical marker called FDG, which measures the metabolic function of cells and has previously been used in aiding diagnosis for Alzheimers disease. However, FDG cannot identify the abnormal brain protein deposits that may cause the disease.
In addition, 72 subjects received magnetic resonance imaging (MRI) scans which show brain structure and size.
Scientists found that FDDNP-PET differentiated between study subject groups better than did the FDG-PET combination or MRI.
"FDDNP yielded excellent diagnostic accuracy and precisely predicted disease progression and brain pathology accum
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Contact: Rachel Champeau
rchampeau@mednet.ucla.edu
310-794-2270
University of California - Los Angeles
20-Dec-2006