Featured Research

from universities, journals, and other organizations

Plaques detected in brain scans forecast cognitive impairment

Date:
March 11, 2014
Source:
Duke Medicine
Summary:
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. 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. 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.

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.

Related Articles


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.

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).


Story Source:

The above story is based on materials provided by Duke Medicine. Note: Materials may be edited for content and length.


Journal Reference:

  1. P M Doraiswamy, R A Sperling, K Johnson, E M Reiman, T Z Wong, M N Sabbagh, C H Sadowsky, A S Fleisher, A Carpenter, A D Joshi, M Lu, M Grundman, M A Mintun, D M Skovronsky, M J Pontecorvo, Ranjan Duara, Marwan Sabbagh, Geoffrey Lawrence Ahern, Richard F Holub, Mildred V Farmer, Beth Emmie Safirstein, Gustavo Alva, Crystal F Longmire, George Jewell, Keith A Johnson, Ron Korn, Eric M Reiman, Jeanette K Wendt, Dean Wong, P Murali Doraiswamy, R Edward Coleman, Michael Devous, Danna Jennings, Michael W Weiner, Cynthia A Murphy, Karel D Kovnat, Jeff D Williamson, Carl H Sadowsky. Florbetapir F 18 amyloid PET and 36-month cognitive decline:a prospective multicenter study. Molecular Psychiatry, 2014; DOI: 10.1038/mp.2014.9

Cite This Page:

Duke Medicine. "Plaques detected in brain scans forecast cognitive impairment." ScienceDaily. ScienceDaily, 11 March 2014. <www.sciencedaily.com/releases/2014/03/140311100324.htm>.
Duke Medicine. (2014, March 11). Plaques detected in brain scans forecast cognitive impairment. ScienceDaily. Retrieved March 2, 2015 from www.sciencedaily.com/releases/2014/03/140311100324.htm
Duke Medicine. "Plaques detected in brain scans forecast cognitive impairment." ScienceDaily. www.sciencedaily.com/releases/2014/03/140311100324.htm (accessed March 2, 2015).

Share This


More From ScienceDaily



More Mind & Brain News

Monday, March 2, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

This Nasal Treatment Could Help Ease Migraine Pain

This Nasal Treatment Could Help Ease Migraine Pain

Newsy (Mar. 2, 2015) Researchers gave lidocaine to 112 patients, and about 88 percent of the subjects said they needed less migraine-relief medicine the next day. Video provided by Newsy
Powered by NewsLook.com
How Facebook Use Can Lead To Depression

How Facebook Use Can Lead To Depression

Newsy (Mar. 1, 2015) Margaret Duffy of the University of Missouri talks about her study on the social network and the envy and depression that Facebook use can cause. Video provided by Newsy
Powered by NewsLook.com
The Best Foods to Battle Stress

The Best Foods to Battle Stress

Buzz60 (Feb. 26, 2015) If you&apos;re dealing with anxiety, there are a few foods that can help. Krystin Goodwin (@krystingoodwin) has the best foods to tame stress. Video provided by Buzz60
Powered by NewsLook.com
Sleeping Too Much Or Too Little Might Increase Stroke Risk

Sleeping Too Much Or Too Little Might Increase Stroke Risk

Newsy (Feb. 26, 2015) People who sleep more than eight hours per night are 45 percent more likely to have a stroke, according to a University of Cambridge study. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins