Researchers using functional magnetic resonance imaging (fMRI) have found a new marker which may aid in early diagnosis of Alzheimer’s disease, according to a study published in the October issue of Radiology.
“The findings of this study implicate a potential functional, rather than structural, brain marker—separate from atrophy—that may help enhance diagnosis and treatment monitoring of Alzheimer’s patients,” said the study’s lead author, Jeffrey R. Petrella, M.D., associate professor of radiology at Duke University Medical Center in Durham, N.C.
Alzheimer’s disease is a progressive brain disorder characterized by memory loss, confusion, personality or behavioral changes and other symptoms. According to the Alzheimer’s Association, more than five million Americans currently have Alzheimer’s disease.
While there is still no cure for the disorder, early diagnosis is crucial so that the patient receives proper treatment.
“As new therapies for Alzheimer’s disease enter the pipeline over the next five years, early diagnosis will become critical for patient selection,” Dr. Petrella said. “fMRI may play a key role in early diagnosis, when combined with clinical, genetic and other imaging markers.”
Among the earliest known changes to the brain in Alzheimer’s disease are episodic memory deficits and structural changes in the medial temporal lobe (MTL). For the study, Dr. Petrella and colleagues set out to identify brain regions in which changes in activation took place during a memory task and to correlate these changes with the degree of memory impairment present in patients with Alzheimer’s disease or mild cognitive impairment.
The researchers studied 13 patients with mild Alzheimer’s disease, 34 patients with mild cognitive impairment and 28 healthy controls. The study group contained 37 men and 38 women with a mean age of 72.9 years. After completing standard neuropsychological testing, the study participants were monitored with fMRI while performing a face-name associative memory task.
While some areas of the brain activate, or turn on their activity, when a person tries to remember something, other areas deactivate, or suppress their activity. Results from this study showed that along the spectrum from healthy people at low risk, to people with mild memory problems, to patients with Alzheimer’s disease, there was increasingly impaired activation in the MTL, an area of the brain associated with episodic memory that normally turns on during a memory task. More surprising, however, was increasingly impaired deactivation in the posteromedial cortices (PMC), an area recently implicated with personal memory that normally suppresses its activity during a memory task. The magnitude of deactivation in the PMC was closely related to the level of memory impairment in the patients and significantly correlated with their neuropsychological testing scores.
While previous studies have suggested that MTL activation may be a possible marker of Alzheimer’s, based on the findings, Dr. Petrella and colleagues concluded that, compared to activation in the MTL, deactivation in the PMC may represent a more sensitive marker of early Alzheimer’s disease.
“In other words, the brain not only loses its ability to turn on in certain regions, but also loses its ability to turn off in other regions, and the latter may be a more sensitive marker. These findings give us insight into how the brain’s memory networks break down, remodel and finally fail as memory impairment ensues,” Dr. Petrella said.
The researchers hope that fMRI will eventually help to identify patients at risk for developing Alzheimer’s disease.
The next step is to conduct a large, multicenter study to see if fMRI can be combined with other imaging and genetic tests to scan for future disease,” said study co-author P. Murali Doraiswamy, M.D., chief of the Division of Biological Psychiatry and Alzheimer’s clinical trial expert at Duke. “Much like a negative colonoscopy gives you reassurance, a normal fMRI may, in the future, also offer predictive value.”
Linda Brooks | EurekAlert!
Penn study identifies new malaria parasites in wild bonobos
21.11.2017 | University of Pennsylvania School of Medicine
NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures
17.11.2017 | National Institute of Standards and Technology (NIST)
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
22.11.2017 | Life Sciences
22.11.2017 | Materials Sciences
22.11.2017 | Life Sciences