Technique moves practical Alzheimer diagnosis one step closer to reality
Researchers at the University of Wisconsin-Madison School of Medicine and Public Health are moving closer to a significant milepost in the battle against Alzheimer's disease: identifying the first signs of decline in the brain.
After years of frustrating failure to stop late-stage Alzheimer's, it's essential to find and treat the mild stages, says Sterling Johnson, professor of geriatrics. "We need to identify Alzheimer's as early as possible, before the really destructive changes take place. Typically, by the time we diagnose Alzheimer's disease, patients have already lost much of their brain capacity, and it's difficult or impossible for them to recover."
The earlier phases, before large numbers of brain cells have been killed, should be more amenable to treatment, Johnson says. Alzheimer's disease is the largest single cause of dementia. Early symptoms include memory decline, eventually progressing to widespread cognitive and behavioral changes.
In a study published in the journal Cerebral Cortex in December, Johnson, Ozioma Okonkwo in the Department of Geriatrics, and colleagues reported on measurements of brain blood flow in 327 adults. The researchers used an advanced form of MRI to compare blood flow in people with Alzheimer's, a preliminary stage called mild cognitive impairment, or those who had no symptoms but had a family history of Alzheimer's.
Reduced blood flow signifies reduced activity in particular parts of the brain, often due to the atrophy of nerve cells. One affected structure, called the hippocampus, is necessary for making new memories. In mild to moderate cases of Alzheimer's, 40 percent or more of the hippocampus has disappeared.
As expected, the Alzheimer's patients had lower blood flow in several brain regions linked to memory. People with mild cognitive impairment had a milder version of the same deficits. And people whose mother (but not father) had Alzheimer's had clear signs of reduced blood flow, even though they lacked symptoms.
Johnson, who is also a neuropsychologist in the Geriatric Research Education and Clinical Center at the William S. Middleton Memorial Veterans Hospital in Madison, is a member of the Alzheimer's Disease Research Center in the School of Medicine and Public Health.
Other techniques that can measure blood flow are more costly and require the use of radiation and injecting a drug tracer during the scan, Johnson says. If this non-invasive MRI technique continues to prove itself, it could be a key to detecting Alzheimer's disease in its early, and hopefully more treatable, phases.
"In the new paper, we showed that the same areas that show up with more established scanning techniques also are identified with this MRI blood flow technique, in people with Alzheimer's and mild cognitive impairment," says Johnson. "So this method is valid and reliable, and is now ready to begin deployment in treatment research with people at risk."
Earlier diagnosis could expand the use of approved drugs that can treat Alzheimer's symptoms, Johnson says, but an immediate benefit would be to streamline trials of chemicals that offer new ways to dissolve the amyloid plaque that is toxic to brain cells.
The need to slow or prevent Alzheimer's grows with the aging population. Despite decades of research, clinical trials have not produced a drug that can definitively halt the advance of Alzheimer's, Johnson says. "Very few drugs have been approved, and they are just for treating symptoms. But I'm getting more optimistic. We understand more with each year, and are very encouraged that we are able to detect Alzheimer's before the onset of dementia."
A trial that focused only on people who are on the path to Alzheimer's and used brain imaging as a marker of disease progression could achieve results on drug effectiveness with 200 subjects that would otherwise require 1,500 or 2,000 people, Johnson says—accelerating the pace for discovering an effective treatment at a lower cost.
In many people, brains are already changing during their 40s and 50s, says Johnson. "This is the time frame we need to focus on, and our imaging methods make this possible. By the time the symptoms are really obvious, it may be too late. Now we can study before the symptoms begin, and someday intervene while there is still a chance to forestall this devastating disease."
Journal reference: Cerebral Cortex
Provided by University of Wisconsin-Madison
- Pfizer and J&J end development of Alzheimer's drug Aug 06, 2012 | not rated yet | 0
- People with early Alzheimer's disease may be more likely to have lower BMI Nov 21, 2011 | not rated yet | 0
- Education protects against pre-Alzheimer's memory loss Oct 20, 2008 | not rated yet | 0
- High blood pressure may heighten effects of Alzheimer's disease Nov 28, 2007 | not rated yet | 0
- Alzheimer's-like brain changes found in cognitively normal elders with amyloid plaques Mar 30, 2011 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Calculating Steam Pressure in Closed Container
2 hours ago I am trying to calculate the volume of liquid water i need to place in a sealed container in order to obtain 10 psi of steam pressure in that closed...
Learning curve of Electromagnetism?
7 hours ago I'm taking a first year physics course and have been having a little trouble with the basics of newtons laws and forces and whatnot, though nothing...
thin glass in liquid
8 hours ago I have one question about optics because I start interested in it. If an object is placed a distance p from a thin glass lens (index of refraction...
How many joules expended for a push up?
11 hours ago Just wondering if any of you can do the calculation that well approximates the amount of joules expended by a push up.
force to keep the folding doors
11 hours ago Hello, I would like to ask you to calculate the force F, which needed to keep the folding doors in this position. I would like to know what is the...
Confusion regarding direction of kinetic friction on inclined plane.
12 hours ago *please help! * The formula for kinetic friction acting on a sliding body is μkN When the body is sliding with constant velocity down an...
- More from Physics Forums - Classical Physics
More news stories
(Medical Xpress)—Working with lab mice models of multiple sclerosis (MS), UC Davis scientists have detected a novel molecular target for the design of drugs that could be safer and more effective than current FDA-approved ...
Alzheimer's disease & dementia May 17, 2013 | 5 / 5 (2) | 0 |
(HealthDay)—Older individuals with nonmelanoma skin cancer (NMSC) seem to have a significantly reduced risk of developing Alzheimer's disease (AD), according to a study published online May 15 in Neurology.
Alzheimer's disease & dementia May 16, 2013 | 5 / 5 (1) | 0
People who have skin cancer may be less likely to develop Alzheimer's disease, according to new research published in the May 15, 2013, online issue of Neurology®, the medical journal of the American Academy of Neurology. The li ...
Alzheimer's disease & dementia May 15, 2013 | 5 / 5 (1) | 0 |
(Medical Xpress)—Scientists at Washington University School of Medicine in St. Louis have helped identify many of the biomarkers for Alzheimer's disease that could potentially predict which patients will develop the disorder ...
Alzheimer's disease & dementia May 14, 2013 | 3 / 5 (1) | 0 |
A drug developed by scientists at the Salk Institute for Biological Studies, known as J147, reverses memory deficits and slows Alzheimer's disease in aged mice following short-term treatment. The findings, ...
Alzheimer's disease & dementia May 13, 2013 | 4.2 / 5 (5) | 0 |
An increasing number of U.S. children are experiencing gastrointestinal issues that require interventions to resolve, according to research presented at Digestive Disease Week (DDW).
11 hours ago | not rated yet | 0 |
The latest makeover to a massive psychiatric tome honored by some, reviled by others and even called the "Bible" of mental disorders is being released Saturday with a host of new changes.
8 hours ago | not rated yet | 0
A new case of the deadly coronavirus has been detected in Saudi Arabia where 15 people have already died after contracting it, the health ministry announced on Saturday on its Internet website.
9 hours ago | not rated yet | 0
Big names in medicine are set to give an upbeat assessment of the war on AIDS on Tuesday, 30 years after French researchers identified the virus that causes the disease.
19 hours ago | 5 / 5 (1) | 0
For combat veterans suffering from post-traumatic stress disorder, 'fear circuitry' in the brain never rests
Chronic trauma can inflict lasting damage to brain regions associated with fear and anxiety. Previous imaging studies of people with post-traumatic stress disorder, or PTSD, have shown that these brain regions can over-or ...
20 hours ago | 5 / 5 (1) | 0 |
A ground-breaking advance in colonoscopy technology signals the future of colorectal care, according to research presented today at Digestive Disease Week(DDW). Additional research focuses on optimizing the minimal withdrawal ...
11 hours ago | 5 / 5 (2) | 0