Why Scratching Relieves An Itch

Daily Science Journal (Feb. 1, 2008) — In the first study to use imaging technology to see what goes on in the brain when we scratch, researchers at Wake Forest University Baptist Medical Center have uncovered new clues about why scratching may be so relieving -- and why it can be hard to stop.

"Our study shows for the first time how scratching may relieve itch," said lead author Gil Yosipovitch, M.D., a dermatologist who specializes in itch. "It's important to understand the mechanism of relief so we can develop more effective treatments. For some people, itch is a chronic condition that affects overall health."

The study involved 13 healthy participants who underwent testing with functional magnetic resonance imaging (MRI) technology that highlights areas of the brain activated during an activity. Participants were scratched on the lower leg with a small brush. The scratching went on for 30 seconds and was then stopped for 30 seconds -- for a total of about five minutes.

"To our surprise, we found that areas of the brain associated with unpleasant or aversive emotions and memories became significantly less active during the scratching," said Yosipovitch. "We know scratching is pleasurable, but we haven't known why. It's possible that scratching may suppress the emotional components of itch and bring about its relief."

The reduced brain activity occurred in the anterior cingulate cortex, an area associated with aversion to unpleasant sensory experiences, and the posterior cingulate cortex, which is associated with memory. When participants reported that the scratching felt most intense, activation in these areas was lowest.

Yosipovitch said patients occasionally report that intense scratching -- to the point of drawing blood -- is the only thing that relieves chronic itch.

"This is the first real scientific evidence showing that itch may be inhibited by scratching," he said. "Of course, scratching is not recommended because it can damage the skin. But understanding how the process works could lead to new treatments. For example, drugs that deactivate this part of the brain might be effective."

The imaging studies also showed that some areas of the brain were made more active by the scratching, including the secondary somatosensory cortex, a sensory area involved in pain, and the prefrontal cortex, which is associated with compulsive behavior.

"This could explain the compulsion to continue scratching," said Yosipovitch.

One drawback to the study is that the scratching occurred in the absence of itch. Yosipovitch's team is continuing the research by evaluating whether the findings will apply to chronic itch.

Understanding more about chronic itch is important, Yosipovitch said, noting that more than 30 million Americans suffer from eczema and that almost half (42 percent) of kidney dialysis patients are bothered by moderate to severe itch. In fact, those kidney dialysis patients with itch have a 17 percent higher mortality rate, likely from a loss of sleep, according to a report in Nephrology Dialysis Transplantation.

The work is reported online in the Journal of Investigative Dermatology and will appear in a future print issue.

The study was supported by the National Institutes of Health and the Center for Biomolecular Imaging of Wake Forest. Co-researchers were Yozo Ishuiji,MD, Tajesh Patel, M.D., Maria Isabel Hicks, M.D., Yoshitetsu Oshiro, M.D., Robert Kraft, Ph.D., Erica Winnicki, M.D., and Robert C. Coghill, Ph.D., senior author, all from Wake Forest.

Adapted from materials provided by Wake Forest University Baptist Medical Center, via EurekAlert!, a service of AAAS.

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Portable Device Quickly Detects Early Alzheimer's

Daily Science Journal (Jan. 17, 2008) — The latest medications can delay the onset of Alzheimer’s disease, but none are able to reverse its devastating effects. This limitation often makes early detection the key to Alzheimer’s patients maintaining a good quality of life for as long as possible.

The DETECT system includes an LCD display in a visor with an onboard dedicated computer, noise reduction headphones and an input device (controller). The display projects the visual aspect of the test and the headphones provide the verbal instructions. (Credit: Image courtesy of Georgia Institute of Technology)

Now, a new device developed by the Georgia Institute of Technology and Emory University may allow patients to take a brief, inexpensive test that could be administered as part of a routine yearly checkup at a doctor’s office to detect mild cognitive impairment (MCI) — often the earliest stage of Alzheimer’s. The device is expected to be commercialized later this year.

Current assessment tests capable of detecting early Alzheimer’s typically are taken with a pen and paper or at a computer terminal and last about an hour and a half. They must be given by a trained technician in a quiet environment, because any distractions can influence the patient’s score and reduce the test’s effectiveness. Because of their length and expense, the tests are not used as regular screening tools and typically are given only after there is obvious cognitive impairment such as forgetfulness or unsafe behavior.

“Families usually wait until their mom or dad does something somewhat dangerous, like forgetting to take their medications or getting lost, before bringing them in for testing. At that point, the patient has already lost a significant portion of their cognitive function,” said David Wright, MD, who helped develop the device. Wright is assistant professor of emergency medicine at Emory University School of Medicine and co-director of the Emory Emergency Medicine Research Center. “With this device, we might be able to pick up impairment well before those serious symptoms occur and start patients on medications that could delay those symptoms.”

The Georgia Tech and Emory device, called DETECT, gives individuals a roughly ten-minute test designed to gauge reaction time and memory — functions that, when impaired, are associated with the earliest stages of Alzheimer’s disease. The test is a specially modified, shortened version of the traditional pen and paper test and could be given repeatedly by doctors to evaluate any changes in cognitive functions.

“We really envision this to be part of the normal preventative care a patient receives from a general practitioner,” said Michelle LaPlaca, Ph.D., one of the creators of the device and an associate professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. “It would be part of a regular preventative medicine exam much like a PSA test or EKG (electrocardiogram), serving as a cognitive impairment vital sign of sorts.”

The portable test runs patients through a battery of visual and auditory stimuli such as pictures and words that assess cognitive abilities relative to age, gauging reaction time and memory capabilities. Its software can track cognitive capabilities — and decline — year to year during annual appointments. And because the device blocks outside sound and light from the patient’s environment, it can be administered in virtually any setting, providing more consistent results.

Preliminary analysis of the first 100 patients of a 400-person clinical study being conducted at Emory’s Wesley Woods Center has shown that the 10-minute DETECT test has similar accuracy to the 90-minute “Gold Standard” pen and paper test.

With millions of baby boomers easing into late adulthood, the number of patients with Alzheimer’s is expected to skyrocket over the next few decades. More than 24 million people worldwide are currently thought to have Alzheimer’s disease and by 2040, an estimated 81 million people worldwide are expected to develop the disease.

To give these millions of potential Alzheimer’s sufferers a chance to slow the disease’s advance before serious symptoms set in, doctors need an inexpensive and easy-to- administer test to detect and track the cognitive decline associated with the early stages of the disease.

The DETECT device is designed to be administered while a patient is still healthy, tracking any abnormal decreases in the patient’s cognitive performance over time. If a patient’s performance declines outside the normal range, the patient would then undergo additional testing and care from a neurologist, neuropsychologist or other specialist.

The DETECT system includes an LCD display in a visor with an onboard dedicated computer, noise reduction headphones and an input device (controller). The display projects the visual aspect of the test, the headphones provide the verbal instructions and the controller records the wearer’s response.

DETECT’s creators have formed a company, called Zenda Technologies, to commercialize the device for MCI, as well as other conditions. Georgia Tech and Emory researchers are exploring other types of cognitive impairment such as Attention Deficit/Hyperactivity Disorder (ADHD) that could be picked up by DETECT. A version of the system designed to detect mild concussions on the sidelines of a football game, during other high-impact sports or on a battlefield is still being tested.

The research was funded with a grant from the Wallace H. Coulter Foundation and support from the Georgia Research Alliance through Georgia Tech’s VentureLab.

Adapted from materials provided by Georgia Institute of Technology.

Related Articles :

• Frequent Brain Stimulation In Old Age Reduces Risk Of Alzheimer's Disease
• Portable Tech/Emory Device Checks For Concussions
• Treatment Causes Short-term, Modest Delay In Alzheimer's Onset In Patients With Mild Cog Impairment
• New Study Shows That Most Older People With Mild Cognitive Impairment Have Alzheimer’s Disease Or Cerebral Vascular Disease
• Urine Test Predicts Alzheimer's Disease
• Distress-prone People More Likely To Develop Memory Problems
• Difficulty Identifying Odors May Predict Cognitive Decline

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High Blood Pressure Associated With Risk For Mild Cognitive Impairment

Daily Science Journal (Dec. 12, 2007) — High blood pressure appears to be associated with an increased risk for mild cognitive impairment, a condition that involves difficulties with thinking and learning, according to a report in the December issue of Archives of Neurology, one of the JAMA/Archives journals.

"Mild cognitive impairment has attracted increasing interest during the past years, particularly as a means of identifying the early stages of Alzheimer's disease as a target for treatment and prevention," the authors write as background information in the article. About 9.9 of every 1,000 elderly individuals without dementia develop mild cognitive impairment yearly. Of those, 10 percent to 12 percent progress to Alzheimer's disease each year, compared with 1 percent to 2 percent of the general population.

Christiane Reitz, M.D., Ph.D., and colleagues at the Columbia University Medical Center, New York, followed 918 Medicare recipients age 65 and older (average age 76.3) without mild cognitive impairment beginning in 1992 through 1994. All participants underwent an initial interview and physical examination, along with tests of cognitive function, and then were examined again approximately every 18 months for an average of 4.7 years. Individuals with mild cognitive impairment had low cognitive scores and a memory complaint, but could still perform daily activities and did not receive a dementia diagnosis.

Over the follow-up period, 334 individuals developed mild cognitive impairment. This included 160 cases of amnestic mild cognitive impairment, which involves low scores on memory portions of the neuropsychological tests, and 174 cases of non-amnestic mild cognitive impairment. Hypertension (high blood pressure) was associated with an increased risk of all types of mild cognitive impairment that was mostly driven by an increased risk of non-amnestic mild cognitive impairment; hypertension was not associated with amnestic mild cognitive impairment, nor with the change over time in memory and language abilities.

"The mechanisms by which blood pressure affects the risk of cognitive impairment or dementia remain unclear," the authors write. "Hypertension may cause cognitive impairment through cerebrovascular disease. Hypertension is a risk factor for subcortical white matter lesions found commonly in Alzheimer's disease. Hypertension may also contribute to a blood-brain barrier dysfunction, which has been suggested to be involved in the cause of Alzheimer's disease. Other possible explanations for the association are shared risk factors," including the formation of cell-damaging compounds known as free radicals.

"Our findings support the hypothesis that hypertension increases the risk of incident mild cognitive impairment, especially non-amnestic mild cognitive impairment," the authors conclude. "Preventing and treating hypertension may have an important impact in lowering the risk of cognitive impairment."

Adapted from materials provided by JAMA and Archives Journals, via EurekAlert!, a service of AAAS.

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Frequent Brain Stimulation In Old Age Reduces Risk Of Alzheimer's Disease

Daily Science Journal (Jul. 28, 2007) — How often old people read a newspaper, play chess, or engage in other mentally stimulating activities is related to risk of developing Alzheimer's disease, according to a new study.

For the study, more than 700 people in Chicago, IL, with an average age of 80 underwent yearly cognitive testing for up to five years. Participants were part of the Rush Memory and Aging Project, a longitudinal study of more than 1,200 older people. Of the participants, 90 developed Alzheimer's disease. Researchers also performed a brain autopsy on the 102 participants who died.

The study found a cognitively active person in old age was 2.6 times less likely to develop dementia and Alzheimer's disease than a cognitively inactive person in old age. This association remained after controlling for past cognitive activity, lifetime socioeconomic status, and current social and physical activity.

Researchers say the findings may be used to help prevent Alzheimer's disease.

"Alzheimer's disease is among the most feared consequences of old age," said study author Robert S. Wilson, PhD, with the Rush Alzheimer's Disease Center at Rush University Medical Center in Chicago. "The enormous public health problems posed by the disease are expected to increase during the coming decades as the proportion of old people in the United States increases. This underscores the urgent need for strategies to prevent the disease or delay its onset."

Wilson says the study also found frequent cognitive activity during old age, such as visiting a library or attending a play, was associated with reduced risk of mild cognitive impairment, a transitional stage between normal aging and dementia, and less rapid decline in cognitive function.

This research was published June 27, 2007, in the online edition of Neurology®, the medical journal of the American Academy of Neurology.

The study was supported by grants from the National Institute on Aging and the Illinois Department of Public Health.

Adapted from materials provided by American Academy of Neurology, via EurekAlert!, a service of AAAS.

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Portable Tech/Emory Device Checks For Concussions

Daily Science Journal (Jul. 25, 2007) — ATLANTA (April 26, 2005) -- A player just took a hard knock to the head and is lying on the field. A coach rushes to his side, but the player sits up and seems fine.

Biomedical Engineering Assistant Professor Michelle LaPlaca demonstrates DETECT with the help of Bryan Williams. The device helps quickly detect mild concussions in virtually any setting. (Image courtesy of Georgia Institute Of Technology)

He knows who the president is and how many fingers the coach is holding up. But is he ready to get back in the game?

More than 750,000 mild traumatic brain injuries (mTBI) occur in the United States each year. When a player or soldier with even a mild concussion is sent back to the field, another blow to the head can lead to additional life long problems or even second impact syndrome, which has a mortality rate of up to 50 percent. But the injury is difficult to diagnose, even with a quiet room and a several-hour-long test.

Michelle LaPlaca, an assistant professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, and David Wright, assistant director of Emory University's Emergency Medicine Research Center, have developed a new device to detect brain injuries right on the sidelines of a football game, on a battlefield or in the emergency room.

Called DETECT (Display Enhanced Testing for Concussions and mTBI system), the device is a fast, easy to administer and sensitive system for assessing problems associated with concussions. The DETECT device is an integrated system that includes software applications, a portable computer and an LCD display in the headgear.

While a typical mTBI test requires a quiet room and 1-2 hours of testing, DETECT performs neuropsychological tests in an immersive environment in about 7 minutes, regardless of surrounding noise and movement. So, a football player or soldier who just took a hard hit to the head can take the test and either be safely cleared to get back on the field or sent to receive medical attention.

The device blocks external stimuli that could interfere with testing, such as light and sound. This allows the test to be given in virtually any setting, even a bright football field with a roaring crowd.

When suffering from mTBI, a person will have difficulty with certain types of thinking controlled by a different areas of the brain, such as working memory, complex reaction and multi-tasking. DETECT runs the wearer through three types of neuropsychological tests that measure the function of several parts of the brain as it attempts to perform the tests.

For example, the first shows the wearer a series of shapes with different colors and textures and gives voice instructions. The wearer uses a simple controller similar to a video game controller to respond to the commands. The device then measures the wearer's response times and answer selections. If the response time is too slow or the incorrect answers were provided, it indicates impairment.

The DETECT system includes a laptop to run the software, a head-mounted display, earmuffs that also act as headphones and an input device (controller). The display projects the visual aspect of the test, the headphones provide the verbal instructions and the controller records the wearer's response.

In addition to the advantages of its speed and portability, DETECT can also be administered by a non-medical personnel such as a coach or parent rather than a trained neurophysiologist.

While the device has already been tested in the lab and in a hospital emergency room, the Georgia Tech football program recognizes the need for improved concussion assessment and plans to test this new technology.

DETECT may have other potential cognitive testing applications, such as helping assess cognitive impairment related to Alzheimer's disease or drug use. The test would be brief and could be performed in a general physician's office.

DETECT is expected to be commercially available in the next three to five years.

Adapted from materials provided by Georgia Institute Of Technology.

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Treatment Causes Short-term, Modest Delay In Alzheimer's Onset In Patients With Mild Cog Impairment

Daily Science Journal (Jul. 20, 2007) — ROCHESTER, Minn. -- For the first time, a drug appears to have a slowing effect -- though limited -- on the progression from mild cognitive impairment, a memory disorder considered a strong early predictor of Alzheimer's disease, to Alzheimer's.

This randomized, double-blind, placebo-controlled, multicenter study compared vitamin E; donepezil, an Alzheimer's treatment drug; and placebo for delay or prevention of progression to Alzheimer's disease in mild cognitive impairment patients. The study's results will be presented at the 9th International Conference on Alzheimer's Disease and Related Disorders in Philadelphia on Sunday, July 18. The Alzheimer's Association described the trial as "among the most anticipated studies" to be presented at the conference.

"This is the first study to demonstrate any positive treatment effect on mild cognitive impairment with respect to progression to Alzheimer's disease," says Ronald Petersen, M.D., Ph.D., Mayo Clinic neurologist and lead investigator of the trial. "We are optimistic because this means we have begun to make progress toward delaying the development of Alzheimer's disease and the cognitive decline that accompanies it."

The study investigators report that vitamin E did not have an effect on slowing the progression to Alzheimer's disease. However, over the first half, or 18 months, of the three-year trial, mild cognitive impairment patients treated with donepezil had a reduced risk of progressing to Alzheimer's disease compared to patients who took placebo; the average delay in disease progression was about six months in those subjects who progressed to Alzheimer's disease. Although the patients treated with donepezil initially progressed to Alzheimer's disease at a slower rate than patients treated with vitamin E or placebo, this risk-reduction effect was short term. By the end of the study, the risk of progression to Alzheimer's disease was the same among all three treatment groups.

"Donepezil appeared to exert its effect during the first half of the study," says Dr. Petersen. "There were a lot of complicating factors, however, and there was no overall risk reduction effect of donepezil by the end of the study. It looks like donepezil had a time-limited, modest effect."

The investigators do not know exactly why donepezil's effect dropped off over time. Theories are that the drug's effect wore off after 18 months, or that the drug exerts a modest effect and then the disease process outweighs the chemical effect of the drug, indicates Dr. Petersen.

Previous studies show that without treatment, about 10 to 15 percent of individuals with mild cognitive impairment progress to Alzheimer's disease each year. Not every patient with mild cognitive impairment will progress to Alzheimer's disease, however.

During the three-year study, the trial participants developed Alzheimer's disease at a rate of 13 percent per year. Among those who progressed to Alzheimer's disease, patients treated with donepezil averaged 661 days until diagnosed with Alzheimer's disease, while those treated with vitamin E averaged 540 days until Alzheimer's diagnosis and those treated with placebo averaged 484 days to Alzheimer's disease.

Due to the complexity of the study's results, the investigators point out that more analysis will be critical to assess the practical implications of the new information and make recommendations for clinical practice.

This study involved 769 participants at 69 medical centers in the United States and Canada. All participants met established criteria for mild cognitive impairment and were randomized to receive vitamin E, donepezil or placebo treatment. Patients who received donepezil were given 5 mg per day for the initial six weeks and then 10 mg till the study's end, and those treated with vitamin E were given 1000 IU per day for the first six weeks and then 2000 IU per day until the study's end. The other participants were given an inactive pill, or placebo. The investigators designed the study to compare the rate of progression from mild cognitive impairment to Alzheimer's disease in each participant group.

The FDA has not approved any treatments for mild cognitive impairment. Vitamin E and donepezil were selected for testing because vitamin E has been shown to delay disease progression in Alzheimer's disease patients and donepezil relieves symptoms of Alzheimer's disease, according to Brad Boeve, M.D., also a Mayo Clinic neurologist and a co-investigator of the trial.

According to the investigators, patients who have mild cognitive impairment have memory impairment that is out of proportion to that expected for their age, yet they do not meet commonly accepted criteria for Alzheimer's disease or other types of dementia. These patients are in a transitional state between early aging and Alzheimer's disease. They can think and reason well, but recent memory is deficient for their age. Researchers have also found that those who have mild cognitive impairment show brain volume loss in the hippocampus, the area of the brain that controls the sorting, storage and recall of information. The condition can be diagnosed on the basis of five criteria:

* Memory complaints

* Abnormal memory for age

* Ability to carry out normal activities of daily living

* Normal general cognitive function

* Lack of dementia

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The National Institute on Aging funded this study, with additional support from Pfizer, Eisai and DSM Nutritional Products.

Adapted from materials provided by Mayo Clinic.

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New Study Shows That Most Older People With Mild Cognitive Impairment Have Alzheimer’s Disease Or Cerebral Vascular Disease

Daily Science Journal (Jul. 17, 2007) — CHICAGO - Mild cognitive impairment in older people is not a normal part of growing old but rather appears to be an indicator of Alzheimer's disease or cerebral vascular disease, according to a study published in the March 8 issue of the journal, Neurology.

"The study shows that mild cognitive impairment is often the earliest clinical manifestation of one or both of two common age-related neurologic diseases," said Dr. David A. Bennett, director of the Rush Alzheimer's Disease Center at Rush University Medical Center and the principal author of the paper. "From a clinical standpoint, even mild loss of cognitive function in older people should not be viewed as normal, but as an indication of a disease process," said Bennett.

This is the first study involving a large number of subjects who were followed until they developed mild cognitive impairment or dementia, and then died.. The study involved examining brain tissue from 180 people, including 37 with mild cognitive impairment, 60 without cognitive impairment, and the rest with dementia. All were Catholic nuns, priest or brothers who agreed to participate in the National Institute on Aging (NIA) funded Religious Orders Study. Since 1993 more than 1000 persons have agreed to annual clinical evaluations and to donate their brains to the Rush investigators at the time of death.

Study participants took tests of memory, language, attention and other cognitive abilities each year to document their clinical status. The diagnosis of mild cognitive impairment (MCI) was made when impaired performance on these tests was not severe enough to warrant a diagnosis of dementia. After death, the investigators measured the amount of Alzheimer's disease pathology and cerebral infarcts (strokes) through brain autopsy. Of the 37 individuals with MCI, more than half (23) met pathologic criteria for Alzheimer's disease, and nearly a third (12) had cerebral infarcts (this include five with both). Less than a quarter (9) did not have either pathology.

"Because most people with mild cognitive impairment progress to dementia, it has been difficult to obtain brain tissue from persons who die while they still have the condition," said Bennett. "We now know that both clinically and pathologically, mild cognitive impairment patients are in the middle in terms of the disease process for Alzheimer's disease and cerebral vascular disease," said Bennett.

One positive finding from the study is that one-third (60) of the total study participants with an average age of 85 did not experience cognitive decline over several years of follow-up. Yet, about half of these persons had significant Alzheimer's disease pathology and nearly a quarter had cerebral vascular disease. "It is likely that these individuals have some type of 'reserve' capacity in their brains that allows them to escape the loss of memory despite the accumulation of pathology," said Bennett.

Bennett and his colleagues are involved in another NIA funded study at Rush, the Memory and Aging Project, trying to identify what keeps these individuals from becoming impaired. "Preventing the accumulation of disease pathology is a common approach to disease prevention," said Bennett. "Another way to prevent loss of cognition is to identify factors that protect us from becoming forgetful despite this pathology.

"From a public health perspective, the number of people with cognitive loss due to Alzheimer's disease and cerebral vascular disease is probably much larger than current estimates," said Bennett. He hopes that these data provide additional impetus to research efforts to develop treatments and, ultimately, prevention for these common diseases of aging.

The study is funded by the National Institute on Aging.

Adapted from materials provided by Rush University.

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Urine Test Predicts Alzheimer's Disease

Daily Science Journal (Jul. 14, 2007) — (Philadelphia, PA) – A urine sample taken at the doctor's office can be the step in determining your chances of developing Alzheimer's disease (AD), according to researchers at the University of Pennsylvania School of Medicine. They have determined that a urine test can reliably detect free radical damage associated with people with Mild Cognitive Impairment (MCI) – a recognized precursor to AD. The test detects isoprostanes, fatty acids that are formed as the result of free radical damage in the brain – damage that correlates with clinical diagnosis of AD.

"This is the first noninvasive test that can predict a clinical diagnosis of Alzheimer's disease," said Domenico Praticò, MD, assistant professor in Penn's Department of Pharmacology. "Since there is no cure for Alzheimer's disease, physicians could slow the course of the disease if it is caught early enough."

Within four years of initial diagnosis, up to 50% of people with MCI develop Alzheimer's disease. As AD progresses, it attacks the brain and causes severe damage in the areas important for memory, judgement, and language. This destruction leads to other clinical complications and, eventually, death.

In the study, published in the June edition of Archives of Neurology, Praticò and his colleagues measured isoprostane in blood and urine samples obtained from 50 patients with a clinical diagnosis of AD, 33 patients with MCI, and 40 healthy volunteers. Two weeks later, a CSF sample and a second urine sample were taken from 28 of the AD patients, 17 of the MCI patients, and 18 of the control subjects. The researchers found significantly higher levels of isoprostane in CSF, blood, and urine of MCI and AD subjects than in the volunteers. Remarkably, the samples taken from the MCI subjects and the volunteers differed only in respect to their isoprostane levels.

"We found that patients with MCI have increased brain oxidative damage before the onset of AD – damage that can be detected in the form of isoprostanes in urine, as this study shows," said Praticò. "In fact, five MCI subjects, all with high isoprostane levels, converted to AD during follow-up."

Patients that are diagnosed with Mild Cognitive Impairment typically present their physicians with persistent memory loss that is not normal for someone of their age and education. Although their memory is impaired, MCI patients are capable of living largely independent lives. At this stage, it is difficult to determine whether a person with MCI will eventually have Alzheimer's or whether they will progress to a form of unrelated dementia.

A urine sample taken in the doctor's office may be a first point of decision in gauging the risk of developing AD. Further tests could then determine the severity of a patient's condition and course of treatment. For example, studies have shown that the transition from MCI to AD occurs fastest in people who have a gene called apoE4 and whose brain's hippocampus region is shown to be smaller as measured in an MRI scan.

"One hypothesis is that, in AD, healthy brain tissue is damaged by the local formation of large amounts of free radicals," said Praticò. "Isoprostanes are the byproducts of fats in the human body that were warped by free radical attack. They then accumulate in CSF, blood, and urine as the body works to get rid of them."

While at the moment this test is not yet clinically available, the team is working on the development of a version of it that could be broadly and easily performed.

Unlike a spinal tap, a urine test is simple to do and provides a painless and noninvasive way of assessing the situation. "The advantages are clear: with an easier test, doctors can diagnose the disease sooner and respond better to the patient's needs," said Praticò.

This research was supported by grants from the National Institutes of Health and the American Heart Association. Trial participants were selected at the Memory Disorders Clinic of Penn's Alzheimer's Disease Center.

Adapted from materials provided by University Of Pennsylvania Medical Center.

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Distress-prone People More Likely To Develop Memory Problems

Daily Science Journal (Jul. 12, 2007) — People who are easily distressed and have more negative emotions are more likely to develop memory problems than more easygoing people, according to a new study.

In the study, those who most often experience negative emotions such as depression and anxiety were 40 percent more likely to develop mild cognitive impairment than those who were least prone to negative emotions. Mild cognitive impairment is a transitional stage between normal aging and dementia. People with mild cognitive impairment have mild memory or cognitive problems, but have no significant disability.

Researchers analyzed the results from two larger studies, the Religious Orders Study and the Memory and Aging Project, which involved 1,256 people with no cognitive impairment. During up to 12 years of follow-up, 482 people developed mild cognitive impairment. Participants were evaluated on their level of proneness to distress and negative emotions by rating their level of agreement with statements such as "I am not a worrier," "I often feel tense and jittery," and "I often get angry at the way people treat me."

"People differ in how they tend to experience and deal with negative emotions and psychological distress, and the way people respond tends to stay the same throughout their adult lives," said study author Robert S. Wilson, PhD, of Rush University Medical Center in Chicago, IL. "These findings suggest that, over a lifetime, chronic experience of stress affects the area of the brain that governs stress response. Unfortunately, that part of the brain also regulates memory."

An earlier study by Wilson and his colleagues showed that people who are easily distressed are more likely to develop Alzheimer's disease than more easygoing people.

Wilson said several factors lead researchers to believe that proneness to stress is a risk factor for memory problems and not an early sign of disease. For example, while the level of distress does not appear to increase in old age, the changes in the brain related to memory problems and Alzheimer's disease do increase with age.

This research was published in the June 12, 2007, issue of Neurology®, the scientific journal of the American Academy of Neurology. The study was supported by grants from the National Institute on Aging and the Illinois Department of Public Health.

Adapted from materials provided by American Academy of Neurology.

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Difficulty Identifying Odors May Predict Cognitive Decline

Daily Science Journal (Jul. 4, 2007) — Older adults who have difficulty identifying common odors may have a greater risk of developing problems with thinking, learning and memory, according to a report in the July issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

Mild cognitive impairment--or a decline in thinking, learning and memory abilities--is increasingly recognized as a precursor to Alzheimer's disease, according to background information in the article. Impairments in the ability to recognize odors have been associated with more rapid cognitive decline and also with the development transition from mild cognitive impairment to Alzheimer's disease. However, little is known about factors that predict the development of mild cognitive impairment.

Robert S. Wilson, Ph.D., of Rush University Medical Center, Chicago, and colleagues studied 589 older adults (average age 79.9) who did not have cognitive impairment in 1997. At that time, the participants took a smell identification test, during which time 12 familiar odors were placed under their nose. They were asked to match each odor to one of four possible alternatives, and were scored from one to 12 based on the number of correct responses. At the beginning of the study and again every year for up to five years, the participants underwent a clinical evaluation that included a medical history, neurological examination and testing of their cognitive function.

During the study, 177 individuals (30.1 percent) developed mild cognitive impairment. Risk of developing mild cognitive impairment increased as odor identification decreased, so that those who scored below average (eight) on the odor identification test were 50 percent more likely to develop the condition than those who scored above average (11). This association did not change when stroke, smoking habits or other factors that might influence smell or cognitive ability were considered. Impaired odor identification was also associated with lower cognitive scores at the beginning of the study and with a more rapid decline in episodic memory (memory of past experiences), semantic memory (memory of words and symbols) and perceptual speed.

"The neurobiological bases of age-associated olfactory dysfunction are uncertain," the authors write. Evidence suggests that even before the symptoms of Alzheimer's disease develop, hallmark tangles develop in certain areas of the brain that may be associated with the processing of smells. Because difficulty identifying odors is associated with other neurological diseases, including Parkinson's disease, other mechanisms are likely involved. "Further clinicopathological and clinicoradiological research on age-related olfactory dysfunction is needed," they continue.

"Among older persons without manifest cognitive impairment, difficulty in identifying odors predicts subsequent development of mild cognitive impairment," the authors conclude. "The findings suggest that olfactory dysfunction can be an early manifestation of Alzheimer's disease ... and that olfactory assessment may be useful for early disease identification."

Adapted from materials provided by JAMA and Archives Journals, via EurekAlert!, a service of AAAS.

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