Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A new technique detects earliest signs of Alzheimer’s in healthy people

25.11.2003


Brain researchers would dearly love to reliably identify changes in brain structure and metabolism associated with early Alzheimer’s disease -- before symptoms emerge.



Such information would buy precious time and perhaps permit potential therapies to delay or even prevent the memory-robbing disease. Now, a new study by NYU School of Medicine researchers brings this goal one step closer to being realized.

Using a new technique to measure the volume of the brain, they were able to identify healthy individuals who would later develop memory impairment, a symptom associated with a high risk for future Alzheimer’s disease. The study is published in the December issue of the journal Radiology.


In the small study, led by Henry Rusinek, Ph.D., Associate Professor of Radiology at NYU School of Medicine, the researchers used MRI scans and a computational formula to measure a region of the brain called the medial-temporal lobe over a period of two years. This area contains the hippocampus and the entorhinal cortex, key structures allied with learning and memory. The researchers found that each year, this region of the brain shrank considerably more in people who developed memory problems compared with people who didn’t. The medial-temporal lobe holds about 30 cubic centimeters -- the equivalent of one-sixth of a cup -- of brain matter in each hemisphere of the brain.

"With our findings, we now know that the normal healthy brain undergoes a predictable shrinkage that can be used to help recognize Alzheimer’s several years before clinical symptoms emerge," says Dr. Rusinek. "We believe this is the first MRI study to report these findings in healthy people, but it is only the first demonstration that extremely early diagnosis is possible, and the technique still requires additional work before it is ready for the clinic," he adds.

The technique was about 90 percent accurate, meaning that it correctly predicted cognitive decline in nine out of 10 people, and it also correctly identified 90 percent of those whose memories would remain normally for their age.

However, the study only involved 45 people; future studies need to ascertain whether the technique would be as accurate in a much larger pool of subjects. In addition, it remains to be shown whether other neurodegenerative diseases that affect the aging brain can also be accurately identified with this technique.

"I believe that this technique opens an era of early diagnosis of Alzheimer’s disease," says Mony J. de Leon, Ed.D., Professor of Psychiatry at NYU School of Medicine and one of the co-authors on the new study. "Now, we want to combine this technique with measurements of certain Alzheimer-related proteins found in the cerebrospinal fluid, to get an even more diagnostically specific assessment," says Dr. de Leon, who is also Director of the Center for Brain Health at the William and Sylvia Silberstein Institute for Aging and Dementia at NYU and a research scientist at the Nathan Kline Institute, an affiliate of NYU School of Medicine, in Orangeburg, N.Y.

Alzheimer’s disease is a progressive illness that kills neurons in the brain, initially causing memory loss and eventually leading to dementia. It afflicts some four million older adults in the United States. Perhaps three times as many individuals suffer early-stage forms of the disease that incapacitate memory to one degree of another. Currently, the disease can be diagnosed definitively only after a person dies, by an autopsy showing certain brain abnormalities.

Previous research by NYU investigators and others has shown that MRI and PET imaging can reveal structural and metabolic changes in the brain that appear to point to early losses in memory and cognitive skills. For example, Dr. de Leon and his colleagues were the first to demonstrate with MRI scans that the hippocampus shrinks in people with mild cognitive impairment (MCI), a form of memory loss that often precedes Alzheimer’s.

Despite the promise of the MRI studies, the hippocampus is notoriously difficult to measure. Shaped like a sea horse and only about four centimeters long (shorter than a pinky), the brain structure yields its exact dimensions unwillingly. The entorhinal cortex is even smaller than the hippocampus, and it, too, is hard to discern clearly.

Faced with these challenges, Dr. Rusinek set out to devise a technique that would be more reliable than currently available methods for measuring atrophy in the region occupied by the hippocampus and entorhinal cortex. He based his technique on a mathematical algorithm created by British researchers for measuring the volume changes of the whole brain, and adapted it to measure a specific region of the brain: the medial-temporal lobe.

Dr. Rusinek reasoned that as long as he was measuring the brain area that contained the hippocampus and the entorhinal cortex, the other structures within his box were inconsequential. "His technique is like fishing with a net," says Dr. de Leon. "The position of the fish in the net doesn’t matter. All that matters is that you are using a big enough net to catch a particular fish."

The new study followed a group of 45 healthy men and women over the age of 60 for six years. At the beginning of the study, everyone was within the normal range on a battery of tests typically used to detect early loss of memory and other mental deficits. Each person received a baseline MRI scan, which was repeated two years later.

Thirteen of the people declined mentally over the course of the study, and six declined after the second MRI scan. Among those who declined, the rate of atrophy in the medial-temporal lobe was the most important variable that distinguished them from the normally aging individuals. The region lost about 0.7 percent of its volume annually -- an amount smaller than the size of a pea. While in the normal aging subjects the region shrank by less than half that volume.

Dr. Rusinek is now attempting to improve the accuracy of the technique by measuring the volume of white and gray matter in the medial-temporal lobe and by improving the spatial resolutions of the MR images. White matter is the fatty insulation around the long, cable-like axons of neurons; gray matter contains the bodies of neurons. In a person with Alzheimer’s disease, the gray matter is largely destroyed. In future studies, Dr. Rusinek expects to find a greater loss of gray matter in people who are likely to develop the kind of cognitive impairment that precedes Alzheimer’s disease.

Pamela McDonnell | EurekAlert!
Further information:
http://www.med.nyu.edu/

More articles from Health and Medicine:

nachricht Study suggests possible new target for treating and preventing Alzheimer's
02.12.2016 | Oregon Health & Science University

nachricht The first analysis of Ewing's sarcoma methyloma opens doors to new treatments
01.12.2016 | IDIBELL-Bellvitge Biomedical Research Institute

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: 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,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

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

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>