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 Penn studies find promise for innovations in liquid biopsies
30.03.2017 | University of Pennsylvania School of Medicine

nachricht 'On-off switch' brings researchers a step closer to potential HIV vaccine
30.03.2017 | University of Nebraska-Lincoln

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: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

'On-off switch' brings researchers a step closer to potential HIV vaccine

30.03.2017 | Health and Medicine

Penn studies find promise for innovations in liquid biopsies

30.03.2017 | Health and Medicine

An LED-based device for imaging radiation induced skin damage

30.03.2017 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>