Molecular imaging detects first signs of Alzheimer's disease

"Molecular imaging of amyloid build-up in the brain will improve the accuracy of diagnosis of Alzheimer's disease and allow physicians to diagnose and treat this chronic disease early on," said Christopher Rowe, M.D., study investigator and professor of nuclear medicine, Austin Hospital, Victoria, Australia. "In the future, the development of an effective anti-amyloid drug may be able to stop the development of dementia if given early, before extensive brain damage in patients has occurred."

Alzheimer's disease is a chronic neurodegenerative disease that kills major centers of the brain controlling memory, language and essential bodily functions. There is currently no cure for Alzheimer's disease, but early diagnosis will increase a patient's chance of effective treatment once a new drug or other therapy is developed to treat the disease.

In the Australian Imaging, Biomarkers and Lifestyle study of aging (AIBL), one of the largest of its kind, researchers in Melbourne and Perth used positron emission tomography (PET), a molecular imaging technique, to detect the formation of beta-amyloid plaques in the brain. The study involved more than 200 elderly participants, including 34 with known Alzheimer's disease and 57 with mild cognitive impairment. Subjects had PET scans using 11C Pittsburgh Compound-B (11C-PIB), a PET imaging agent that binds to beta-amyloid in neural tissues. Results of the two-year study showed that beta-amyloid plaque builds slowly over time, and extensive build-up of the protein preceded cognitive impairment and was associated with 13 times the level of risk of progressing to Alzheimer's disease within 20 months. Researchers found that development of the disease could begin as early as 10 years before signs of dementia. Patients with a strong family history of Alzheimer's or who show mild signs of memory loss could be screened for the development of the disease in order to help them plan for the future. This imaging technique could also be used to evaluate the effectiveness of new treatments as they become available.

The risk of Alzheimer's disease increases steadily with age, affecting an estimated 25 percent of people aged 85. According to the World Health Organization, approximately 18 million people are currently living with Alzheimer's disease worldwide -- a number projected to almost double by 2025.

Scientific Paper 383: V.L. Villemagne, K. Pike, R.S. Mulligan, G. Jones, C.C. Rowe, Centre for PET, Austin Hospital, Melbourne, Victoria, Australia; K.A. Ellis, Psychiatry, University of Melbourne, Melbourne, Victoria, Australia; P. Bourgeat, O. Salvado, CSIRO Preventative Health National Research Flagship, Brisbane, Queensland, Australia; D. Ames, National Ageing Research Institute, Melbourne, Victoria, Australia; C.L. Masters, The Mental Health Research Institute, Melbourne, Victoria, Australia; "Longitudinal assessment of Aβ burden and cognition with 11C-PiB PET in aging and Alzheimer's disease," SNM's 57th Annual Meeting, June 5-9, 2010, Salt Lake City, Utah.