Alzheimer's Damage in Early-Stage is identified as a novel MRI approach

Alzheimer's Damage in Early-Stage is identified as a novel MRI approach ...

Alzheimer''s disease is usually diagnosed based on symptoms, such as when a person shows signs of memory loss and difficulty thinking. In clinical practice, MRI brain scans haven''t proven beneficial for early diagnosis. However, these tests have failed to prove useful for early diagnosis. However, the signs of brain shrinkage only become unmistakable late in the course of the disease, long after the brain is significantly damaged and most people have been diagnosed via other means.

A mathematical analysis of data obtained with a novel MRI technique can identifie brain cell damage in people at early stages of Alzheimers, so that tissue shrinkage is not seen on traditional MRI scans, and that cognitive symptoms will arise.

According to senior authorDmitriy Yablonskiy, a PhD, a radiology professor at the University of Minnesota, the technique takes only six minutes to acquire data and can be applied on MRI scanners already used worldwide for patient diagnostics and clinical trials.

The study, published in the Journal of Alzheimers Disease, focuses on a new quantitative Gradient Echo (qGRE) MRI technique developed in the Yablonskiy laboratory to detect brain areas that are no longer functioning due to a loss of healthy neurons.

We analyzed brain areas that looked similar on traditional MRI but were less noticeable on QGRE images, according to science and the first author of the study. They were then classified as dark matter.

Despite demonstrating where damaged areas of the brain have decreased in volume, the qGRE technique goes a step further, detecting brain losses that precede brain shrinkage and cognitive decline.

Alzheimers disease develops slowly over the course of two decades or more before symptoms arise. First the brain protein amyloid beta accumulates into plaques in the brain, then another brain protein tau coalesces into tangles, and neurons begin to die. Finally, tissue atrophy can be identified through amyloid-PET brain scans or by testing for amyloid in the blood or the cerebrospinal fluid that surrounds the brain and spinal cord, but such tests do not provide information.

TheCharles F. and Joanne Knight Alzheimer Disease Research Center (Knight ADRC) recruited 70 individuals aged 60 to 90. Participants completed extensive clinical and cognitive examinations to assess their level of cognitive impairment. The group included individuals with little cognitive impairment, as well as those with very mild, mild or moderate impairments.

Chaque participant undergoes either a PET brain scan or a spinal tap to determine the amount of amyloid plaques in his or her brain. They also undergo MRI brain scans.

Researchers used the qGRE MRI technique to diagnose the hippocampus, the brains memory center, and one of the early affected brain regions in Alzheimers. They found that the hippocampus often contained a viable tissue section with relatively preserved neurons and a dark matter dead zone that is virtually devoid of healthy neurons.

These dark matter areas were present in people who tested positive for amyloid but weren''t yet experiencing symptoms, and they grew larger as the disease grew. Compared to traditional MRI methods of brain atrophy, biomarkers for dark matter correlated significantly better with individual cognitive scores for very mild to moderate dementia.

Alzheimers research that took place at Washington University more than two decades ago, when Alzheimers was formally diagnosed only through autopsy, is based on and corroborates the findings.

In 2001, John C. Morris, MD, the Harvey A. and Dorismae Hacker Friedman, Distinguished Professor of Neurology and Director of the Knight ADRC, conducted a research that examined the brain tissue of deceased Alzheimers patients and discovered that damaged brain regions had begun to lose healthy neurons well before the disease caused significant brain volume loss in these areas.

After the early 2000s, Tammie L. S. Benzinger, MD, a radiology and neurosurgery professor, and the Knight ADRCs director, was among the pioneers at the Mallinckrodt Institute of Radiology to use PET brain scans targeted against amyloid beta as a tool for diagnosing Alzheimers.

Researchers found a similar relationship between neuronal loss and Alzheimers symptoms in living patients using the non-invasive qGRE MRI technique.

The research team, which works with Dr. Rick Perrin, MD, and an associate professor of pathology and immunology, verified this relationship under the microscope by studying brain tissues that were donated following the death of a study participant. The postmortem examination found that the neuronal loss in the hippocampus actually exceeded the loss of tissue volume and that these changes are well shown in MRI findings of dark matter.

Yablonskiy and colleagues are among the many individuals working on a low-cost, well-accessible Alzheimers test as a replacement to PET brain scans and invasive spinal taps used in research sites to determine the present and progression of the disease.

A formal screening of patients for clinical trials, particularly one that can identify people at very early stages of disease, would give the world a boost to Alzheimers research, reducing the cost and duration of the study. This will help develop innovative therapies.

Despite the fact that Alzheimers researchers continue to pursue therapeutic treatments for the disease, most experts predict that a successful treatment will consist of early detection and a selection of techniques to relieve brain damage before reaching later stages of Alzheimers.

Both PET scans and spinal taps continue to play a vital role in Alzheimers research, but both have limitations that make them available as a screening tool for early signs.

PET brain scans are still the gold standard for Alzheimers detection, but the machines are costly and rarely available for routine patient diagnosis, although PET scans are also required for brain imaging.

Alzheimers may be detected by testing for tau proteins in cerebrospinal fluid, but sampling requires a spinal tap that may be too invasive for use as a general screening tool, especially for people who have no symptoms.

Another great option for Alzheimers screening is a non-invasive, relatively inexpensive blood test that has proved to be very effective in diagnosing early signs of Alzheimers disease. A commercial version of the blood test has recently been available to doctors in the United States and Europe, although it isn''t yet covered by health insurance.

qGRE MRI technique may be developed early on because it is based on MRI technology that is widely available worldwide, noninvasive and can be used without the use of radioactive tracers.

Our qGRE test is of great use as an early diagnostic tool for Alzheimers disease''s preclinical stage, thus providing a wide spectrum of therapeutic treatment options, according to Yablonskiy. It also has the potential to offer a noninvasive MRI technique in a conventional clinical setting for the widespread screening required to get people with early Alzheimers into clinical trials.

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