Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Plaques detected in brain scans forecast cognitive impairment

11.03.2014

Brain imaging using radioactive dye can detect early evidence of Alzheimer's disease that may predict future cognitive decline among adults with mild or no cognitive impairment, according to a 36-month follow-up study led by Duke Medicine.

The national, multicenter study confirms earlier findings suggesting that identifying silent beta-amyloid plaque build-up in the brain could help guide care and treatment decisions for patients at risk for Alzheimer's. The findings appeared online March 11, 2014, in Molecular Psychiatry, a Nature Publishing Group journal.

"Our research found that healthy adults and those with mild memory loss who have a positive scan for these plaques have a much faster rate of decline on memory, language and reasoning over three years," said lead author P. Murali Doraiswamy, M.D., professor of psychiatry and director of the neurocognitive disorders program at Duke.

Alzheimer's disease – which currently has no cure – afflicts an estimated five million U.S. adults, and is the sixth-leading cause of death among adults, according to the Centers for Disease Control and Prevention. Prior studies have found that changes in the brain begin years, and possibly decades, before cognitive symptoms emerge.

... more about:
»Alzheimer's »PET »Plaques »cognitive »scans

A biomarker that could accurately identify those at greatest risk for cognitive decline could help clinicians better evaluate and treat patients, while also accelerating the testing of drugs to treat the disease.

The current study, which enrolled 152 adults ages 50 and older, was designed to assess whether silent pathological changes in the brain associated with Alzheimer's and detected with positron emission tomography (PET) can predict cognitive decline. Of the participants, 69 had normal cognitive function at the start of the study, 52 had been recently diagnosed with mild cognitive impairment, and 31 were diagnosed with Alzheimer's disease.

Subjects completed cognitive tests and underwent PET scans of their brains. This type of imaging uses a radioactive tracer to look for chemical signs of disease in specific tissues.

The radioactive dye used, florbetapir (Amyvid), was approved by the U.S. Food and Drug Administration in 2012 for PET imaging of the brain to estimate beta-amyloid plaque density in patients being evaluated for cognitive impairment. It binds to the beta-amyloid plaques that characterize Alzheimer's disease, helping to measure the extent to which plaques have formed in different brain regions. Using this information, the researchers rated the PET scans as positive or negative.

After 36 months, the researchers repeated the same cognitive exams to reassess participants. They found that those with mild or no cognitive impairment who had evidence of plaques at the trial's start worsened to a greater degree on cognitive tests than those with negative scans.

Thirty-five percent of plaque-positive participants who started with mild cognitive impairment progressed to Alzheimer's, compared to 10 percent without plaque. In addition, plaque-positive participants with mild impairment were more than twice as likely to be started on cognitive-enhancing medication than those without plaque.

Conversely, those with negative scans experienced much less decline: 90 percent of participants with mild cognitive impairment but no plaque did not progress to Alzheimer's. This finding supports the negative predictive value of using PET imaging to identify patients unlikely to decline, which has important implications for both clinical research and treatment.

"Having a negative scan could reassure people that they are not likely to be at risk for progression in the near future," Doraiswamy said.

Doraiswamy cautioned that florbetapir is currently not approved to predict the development of dementia and is not used as a screening tool in cognitively normal people. Future longitudinal studies are needed to further clarify the prognostic role of beta-amyloid plaque PET imaging in a clinical setting.

"Even though our study suggests the test has predictive value in normal adults, we still need additional evidence," Doraiswamy said. "We need longer-term studies to look at the consequences of silent brain plaque build-up, given that it affects 15 to 30 percent of normal older people."

Doraiswamy added that the findings provide support for planned and ongoing multicenter clinical trials of asymptomatic older adults with plaque-positive scans. The research also has implications for other conditions where amyloid might play a role, such as traumatic brain injury (from sports or combat).

###

In addition to Doraiswamy, study authors include Terence Z. Wong of Duke (currently at the University of North Carolina at Chapel Hill); Reisa A. Sperling and Keith Johnson of Massachusetts General Hospital, Harvard Medical School; Eric M. Reiman of Banner Alzheimer's Institute; Marwan N. Sabbagh of Banner-Sun Health Research Institute; Carl H. Sadowsky of Nova SE University; Michael Grundman of Global R&D Partners and the University of California, San Diego; Adam S. Fleisher of Banner Alzheimer's Institute and the University of California, San Diego; and Alan Carpenter, Abhinay D. Joshi, Ming Lu, Mark A. Mintun, Daniel M. Skovronsky and Michael J. Pontecorvo of Avid Radiopharmaceuticals.

The study was funded by Eli Lilly/Avid Radiopharmaceuticals, which markets florbetapir, and was conducted by Avid and the AV45-A11 study group, a consortium of Alzheimer's clinical research centers. Doraiswamy receives advisory and speaker fees from Lilly/Avid, as well as other companies. A full list of author disclosures can be found in the manuscript.

Rachel Harrison | EurekAlert!
Further information:
http://www.dukemednews.org/

Further reports about: Alzheimer's PET Plaques cognitive scans

More articles from Health and Medicine:

nachricht Oxygen can wake up dormant bacteria for antibiotic attacks
08.12.2016 | Penn State

nachricht NTU scientists build new ultrasound device using 3-D printing technology
07.12.2016 | Nanyang Technological University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Will Earth still exist 5 billion years from now?

08.12.2016 | Physics and Astronomy

Oxygen can wake up dormant bacteria for antibiotic attacks

08.12.2016 | Health and Medicine

Newly discovered bacteria-binding protein in the intestine

08.12.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>