Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Advanced analysis of brain structure shape may track progression to Alzheimer's disease

26.10.2016

MRI data reveals structural asymmetries that vary among individuals, are greater among those who develop dementia

Use of a novel approach to analyzing brain structure that focuses on the shape rather than the size of particular features may allow identification of individuals in early presymptomatic stages of Alzheimer's disease. A team of Massachusetts General Hospital (MGH) investigators using advanced computational tools to analyze data from standard MRI scans report that individuals with Alzheimer's disease, including those diagnosed partway through a multi-year study, had greater levels of asymmetry - differences in shape between the left and right sides of the brain - of key brain structures. Their study has been published online in the journal Brain.


Computational model of the cortical and subcortical brain structures that form the basis of the BrainPrint, a system for representing the whole brain based on the shape, rather than the size of structures.

Credit: Martin Reuter, Ph.D., and Christian Wachinger, Ph.D., Martinos Center for Biomedical Imaging, Massachusetts General Hospital

"Our results show for the first time that asymmetry of the hippocampus and amygdala increases with disease severity, above and beyond age-associated effects," says Christian Wachinger, PhD, formerly with the Martinos Center for Biomedical Imaging at MGH, the lead author of the report. "By studying the progression of asymmetry from mild cognitive impairment to dementia, we demonstrated that greater asymmetry in those and a few other structures can predict disease progression and could be a biomarker allowing early detection of dementia."

Wachinger is part of a team led by Martin Reuter, PhD, of the Martinos Center, that developed BrainPrint, a computer-aided system for representing the whole brain based on the shapes rather than the size or volume of structures. Originally described in a 2015 article in NeuroImage, BrainPrint appears to be as accurate as a fingerprint in distinguishing among individuals. In a recent paper in the same journal, Wachinger and Reuter demonstrated the use of BrainPrint for automated diagnosis of Alzheimer's disease.

The current study used BrainPrint to analyze structural asymmetries in a series of MR images of almost 700 participants in the National Institute of Health-sponsored Alzheimer's Disease Neuroimaging Initiative (ADNI). Participation in that study involves MR brain imaging taken upon enrollment and repeated every 6 to 12 months, along with cognitive and genetic testing; and the MGH study analyzed data from ADNI participants with at least three MRI scans. Participants were divided into four groups: those diagnosed with probable Alzheimer's when entering the study, healthy controls with no sign of dementia, individuals with mild cognitive impairment that remained stable over the two to three years for which scans were available, and those with mild cognitive impairment that progressed to Alzheimer's disease during the study.

BrainPrint analysis of the data revealed that initial, between-hemisphere differences in the shapes of the hippocampus and amygdala - structures known to be sites of neurodegeneration in Alzheimer's disease - were highest in individuals with dementia and lowest in healthy controls. Among those originally classified with mild cognitive impairment, baseline asymmetry was higher in those that progressed to Alzheimer's dementia and became even greater as symptoms developed. Increased asymmetry was also associated with poorer cognitive test scores and with increased cortical atrophy.

The senior author of the Brain paper, Reuter explains, "Several studies have indicated that Alzheimer's has different effects in different sub-structures of the hippocampus and amygdala. Since the shape descriptors of BrainPrint are more sensitive to subtle changes within a structure than are standard volume-based measures, they are better suited to quantify early disease effects and predict future progression, which opens up new research directions into the mechanisms that cause these asymmetries. For example, in addition to asymmetric distribution of amyloid beta, which has been reported, the differences could reflect disease subtypes that affect hemispheres differently."

Now a professor of Neurobiological Research in the Department of Child and Adolescent Psychiatry, Psychosomatics, and Psychotherapy at Ludwig Maximilian University of Munich, Wachinger adds, "In collaboration with colleagues at the Martinos Center, we are planning further exploration of the relationship between shape asymmetries and established Alzheimer's disease biomarkers to better understand the underlying biological mechanisms. Differentiating between those with stable mild cognitive impairment and those who will progress to Alzheimer's is of great clinical relevance, as it could help select individuals appropriate for clinical trials of disease-modifying therapies."

###

Reuter is an assistant professor of Radiology and of Neurology at Harvard Medical School and director of the Laboratory for Computational Longitudinal Neuroimaging at the Martinos Center. He also holds a research affiliation at the Massachusetts Institute of Technology. Additional co-authors of the Brain paper are David Salat, PhD, Martinos Center, and Michael Weiner, MD, University of California, San Francisco. Support for the study includes National Institutes of Health grant 1K25CA181632, Massachusetts Alzheimer's Disease Research Center grant 5P50AG005134, and grants from the Humboldt Foundation, MGH Neurology Clinical Trials Unit, the Harvard NeuroDiscovery Center, and the Genentech Foundation.

Massachusetts General Hospital, founded in 1811, is the original and largest teaching hospital of Harvard Medical School. The MGH Research Institute conducts the largest hospital-based research program in the nation, with an annual research budget of more than $800 million and major research centers in HIV/AIDS, cardiovascular research, cancer, computational and integrative biology, cutaneous biology, human genetics, medical imaging, neurodegenerative disorders, regenerative medicine, reproductive biology, systems biology, photomedicine and transplantation biology. The MGH topped the 2015 Nature Index list of health care organizations publishing in leading scientific journals, earned the prestigious 2015 Foster G. McGaw Prize for Excellence in Community Service. In August 2016 the MGH was once again named to the Honor Roll in the U.S. News & World Report list of "America's Best Hospitals."

Terri Ogan | EurekAlert!

More articles from Health and Medicine:

nachricht One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center

nachricht The gut microbiota plays a key role in treatment with classic diabetes medication
01.06.2017 | University of Gothenburg

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: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>