Diagnosis & assessment of Alzheimer's Disease: Brief summaries of research reports

Early Markers

Women lose weight at least a decade before developing dementia

Simple test predicts 6-year risk of dementia

Brain structure changes years before memory loss begins

Memory complaints early warning for Alzheimer's

New early diagnostic test trialed

Link between increased weight-loss rate and dementia

Weight Loss Precedes Dementia Diagnosis In Women

Alzheimer's disease onset tied to lapses in attention

A new analysis of a standard brain test may help predict dementia

Biosensor reveals new information about ADDLs

Protein studies may lead to new Alzheimer's test

New test is first step in early detection of Alzheimer's disease

Smell test to help early diagnosis

Antibody detection in Alzheimer's may improve diagnosis, treatment

Loss of smell linked to key protein in Alzheimer's disease

Diagnosing Alzheimer's disease may soon be possible earlier

Gene marker for late-onset Alzheimer's disease nearer discovery

August 2007

Women lose weight at least a decade before developing dementia

Another study has come out associating weight loss with later dementia. The study found that women who later developed dementia started losing weight up to 20 years before the disease was diagnosed. On average, those with dementia weighed 12 pounds less than those without the disease the year the disease was diagnosed. The association may be related to a loss in the sense of smell, and increasing apathy. The association was not found with men, probably because older men were less likely to be preparing their own food. The findings do of course conflict with others suggesting that obesity in middle-age may be a risk factor for dementia. More research is needed to clarify the situation.
The study was published in the August 21 issue of Neurology.    Full reference
http://www.eurekalert.org/pub_releases/2007-08/aaon-wlw081407.php

June 2007

Simple test predicts 6-year risk of dementia

A 14-point index combining medical history, cognitive testing, and physical examination — a simple test that can be given by any physician — has been found to predict a person’s risk for developing dementia within six years with 87% accuracy. As measured by the index, the risk factors for developing dementia are an age of 70 or older, poor scores on two simple cognitive tests, slow physical functioning on everyday tasks such as buttoning a shirt or walking 15 feet, a history of coronary artery bypass surgery, a body mass index of less than 18, and current non-consumption of alcohol. The results do need to be validated in other populations — for example, they have not yet been tested on Hispanics or Asian-Americans.
The tests were described in a presentation at the 2007 International Conference on Prevention of Dementia, in Washington, DC.
http://www.eurekalert.org/pub_releases/2007-06/uoc--stp060707.htm

April 2007

Brain structure changes years before memory loss begins

Another study provides evidence that people who develop dementia or Alzheimer's disease experience brain structure changes years before any signs of memory loss begin. The study involved 136 people over the age of 65 who were considered cognitively normal at the beginning of the five-year study. By the end of the study, 23 people had developed MCI, and nine of the 23 went on to be diagnosed with Alzheimer's disease. Compared to the group that didn't develop memory problems, the 23 who developed MCI or Alzheimer's disease had less gray matter in key memory processing areas (specifically, anteromedial temporal lobes and left angular gyrus) even at the beginning of the study when they were cognitively normal. They also had lower cognitive test scores, though these scores were still within normal range.
The study was published in the April 17 issue of Neurology. Full reference
http://www.eurekalert.org/pub_releases/2007-04/aaon-bsc041007.htm

November 2006

Memory complaints early warning for Alzheimer's

A post-mortem study of 90 older adults from the Rush Memory and Aging Project found that those who had yet to have any clinical symptoms of Alzheimer's disease still showed a strong link between their self-reported memory complaints and brain pathology associated with Alzheimer's disease.
The findings were reported in the November issue of Neurology. Full reference
http://www.eurekalert.org/pub_releases/2006-11/rumc-cam113006.htm

September 2006

New early diagnostic test trialed

A mouse study has used a laser scan of the eyes to accurately diagnose Alzheimer's well before the disease was evident in the brain. The study follows on from earlier research revealing that beta-amyloid protein is evident in the eyes of Alzheimer’s patients. The test, which is a very quick and simple procedure, is now in the first stage of experimental trials in people.
The findings were announced at the annual meeting of the Optical Society of America.
http://www.sciencentral.com/articles/view.htm3?article_id=218392859

Link between increased weight-loss rate and dementia

Confirming earlier indications, a long-term study of the elderly has revealed that their average rate of weight loss doubles (from 0.6 pounds per year to 1.2 pounds per year) in the year before symptoms of Alzheimer's-type dementia first become detectable. The finding may be useful as one of several early biomarkers. The study analyzed data on 449 seniors, of whom 125 were eventually diagnosed with mild dementia. Interestingly, at the beginning of the study, this group weighed about 8lb less on average than the other participants, although the two groups lost weight at the same rate for four to five years, before weight loss increased in the group that would eventually be diagnosed with mild dementia. It is not yet known why there should be this connection between weight loss and dementia.
The report appeared in the September issue of Archives of Neurology. Full reference
http://www.eurekalert.org/pub_releases/2006-09/wuso-bdf090806.htm

July 2006

Weight Loss Precedes Dementia Diagnosis In Women

A study has come out finding that, in women, declining weight precedes dementia by many years.
The retrospective study analyzed the medical records of 560 patients diagnosed with the onset of dementia between 1990 and 1994. The patients were matched with 560 controls. Among the women, average weight increased slightly over the preceding 30 years for the control group, but drifted downwards over the 30 years for those who developed dementia. The researchers suggest that changes in the brain interfered somehow with maintenance of body weight. The trend was not observed in men.
Findings were presented July 16 at the Alzheimer's Association International Conference on Alzheimer's Disease and Related Disorders in Madrid, Spain.
http://www.sciencedaily.com/releases/2006/07/060716090233.htm

November 2005

Alzheimer's disease onset tied to lapses in attention

A new finding may lead to another tool to detect Alzheimer’s early, and also offers support for the idea that breakdowns in attention may be at the heart of many of the memory problems experienced by Alzheimer’s sufferers. The study, involving 94 older adults (average age mid-70s) who were either healthy controls or in the early stages of Alzheimer’s, found those in the early stages of Alzheimer's disease had greater difficulty shifting attention back and forth between competing sources of information in a dichotic listening task. The finding may also explain why early-stage patients start to struggle with everyday tasks that call for processing a lot of information, such as driving. Prior research has found that performance on dichotic listening predicts accident rates in commercial bus drivers.
[note: this study was briefly reported on in September, but only mentioning its use as an early test]
The study was published in the September issue of Neuropsychology. Full reference
Full text is available at: www.apa.org/journals/releases/neu195687.pdf
http://www.eurekalert.org/pub_releases/2005-11/wuis-ado110905.htm

October 2005

A new analysis of a standard brain test may help predict dementia

A new study gives promise of early diagnosis of Alzheimer’s. A computer analysis of an EEG (electroencephalograph) test was almost 95% accurate in predicting those people in their 60s and 70s who would develop dementia over the next 7 to 10 years. There were several distinctive features in the brain waves of those who would later show cognitive impairment. The study now needs to be replicated with a larger sample.
The study was published online on 6 October in Neurobiology of Aging. Full reference
http://www.eurekalert.org/pub_releases/2005-10/dumc-ana100505.htm

August 2005

Biosensor reveals new information about ADDLs

A new method using nanoscale optical biosensors allows researchers to detect and estimate the size and structure of ADDLs in cerebrospinal fluid. It’s believed that only ADDLs of a certain size cause problems for neurons in the early stages of Alzheimer’s disease. It is hoped that eventually this technology will help us diagnose Alzheimer’s accurately in living people, and aid our understanding of how ADDLs are involved in Alzheimer’s.
The findings were presented on August 31 at the 230th national meeting of the American Chemical Society. Reference
http://www.eurekalert.org/pub_releases/2005-08/acs-brn081905.htm

April 2005

Protein studies may lead to new Alzheimer's test

A new technique has identified more than 400 proteins in human spinal fluid — 40 times more than previously known. On average, one of every five proteins identified was substantially changed in patients with Alzheimer's disease compared to older people without neurological disease. The finding may lead to a new test for diagnosing Alzheimer’s.
The study appeared in the April issue of the Journal of Alzheimer's Disease. Full reference
http://www.eurekalert.org/pub_releases/2005-04/uow-psm041905.htm

January 2005

New test is first step in early detection of Alzheimer's disease

A new technique called bio-bar-code amplification (BCA) technology has been found to be able to detect miniscule amounts of ADDL in human cerebrospinal fluid, bringing promise of an early diagnostic test for Alzheimer’s. The researchers hope to develop the technology so that the test could be done using a blood or urine sample instead of cerebrospinal fluid, which is more difficult to obtain.
The findings were published online the week of January 31 in the Proceedings of the National Academy of Sciences.
Full reference
http://www.eurekalert.org/pub_releases/2005-01/nu-nti012805.htm
http://www.eurekalert.org/pub_releases/2005-01/nsf-nds012805.htm

December 2004

Smell test to help early diagnosis

One of the first types of memory affected by Alzheimer’s is olfactory memory – our database of smells. Researchers have now developed a simple scratch-and-sniff test that may enable Alzheimer’s to be detected in its very early stages. On the basis of a five-year study tracking 150 people with mild memory loss and Alzheimer's disease and 63 healthy adults, 10 specific odors proved to be the best predictors for Alzheimer's Disease: strawberry, smoke, soap, menthol, clove, pineapple, natural gas, lilac, lemon and leather. The test takes only 5 to 8 minutes, and seems to have comparable predictive ability as detailed memory and neuropsychological testing.
The findings were presented at the 2004 meeting of the American College of Neuropsychopharmacology.
http://www.sciencentral.com/articles/view.htm3?article_id=218392445
http://www.eurekalert.org/pub_releases/2004-12/g-sfl121004.htm

June 2004

Antibody detection in Alzheimer's may improve diagnosis, treatment

A study has found that people with Alzheimer’s disease have three to four times more antibodies to RAGE (receptor for advanced glycation end products) and beta amyloid — both major players in Alzheimer’s — than their healthy counterparts. The ability to measure these specific antibody levels could lead to a method for very early diagnosis. The finding may also point to a new treatment approach. The study supports the theory that autoimmunity and resulting inflammation play a big role in Alzheimer’s.
The report is scheduled for publication in the September issue of Neurobiology of Aging. Full reference
http://www.eurekalert.org/pub_releases/2004-06/mcog-adi060204.htm

March 2004

Loss of smell linked to key protein in Alzheimer's disease

Loss of smell is one of the first clinical signs of Alzheimer’s and Parkinson’s disease. Now researchers have linked smell loss in genetically altered mice with excessive levels of a key protein associated with these diseases. If smell function declines as the levels of this protein increase in brain regions associated with smelling, the research could validate the use of smell tests for diagnosing Alzheimer's disease.
Their findings appear in the March 12th issue of Brain Research, the commemorative volume 1000. Full reference
http://www.eurekalert.org/pub_releases/2004-03/uopm-los030304.htm

March 2001

Diagnosing Alzheimer's disease may soon be possible earlier

Diagnosing Alzheimer's disease is problematic because we have had no definitive tests for the disease (other than after death, by examining the brain). Recent research suggests that two markers in cerebrospinal fluid may indicate the presence of Alzheimers. This is exciting not only because it would make diagnosis easier, but because it might enable us to diagnose it much earlier. However, to be clinically useful, they will need to develop tests that use more readily available fluids (such as urine).
The study appeared in the November issue of the Annals of Neurology.

December 2000

Gene marker for late-onset Alzheimer's disease nearer discovery

Three independent studies have linked late-onset Alzheimer's disease to a locus on chromosome 10 that affects processing of the amyloid-beta protein, a peptide important in the formation of the characteristic amyloid plaques found in the brains of people with Alzheimer's disease. Researchers are optimistic the precise gene will be found in the next few years.
Before this, a particular form of the apolipoprotein E (APOE) gene on chromosome 19 has been the only widely recognized genetic risk factor in late onset Alzheimer’s disease. There is also some evidence of a risk factor gene on a region of chromosome 12.
So far, three genes have been found that are linked to the rare early-onset Alzheimer's (when symptoms appear before age 60).
The findings are reported in the Dec. 22 issue of Science.
http://www.eurekalert.org/pub_releases/2000-12/MCJ-Loc1-2112100.htm

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Cognitive tests

Simple test predicts 6-year risk of dementia

Personality changes may help detect Lewy bodies dementia

New dementia screening tool detects early cognitive problems

More sensitive tests for predicting Alzheimer's

Early warning signs of Alzheimer's show up years before official diagnosis

More sensitive test norms better predict who might develop Alzheimer's disease

New method of distinguishing Alzheimer's from Lewy body dementia

Brief telephone questionnaire screens for early signs of dementia

Verbal memory tests predict dementia

Verbal memory test best indicator of who will have Alzheimer's disease

Early diagnosis of Alzheimer's

June 2007

Simple test predicts 6-year risk of dementia

A 14-point index combining medical history, cognitive testing, and physical examination — a simple test that can be given by any physician — has been found to predict a person’s risk for developing dementia within six years with 87% accuracy. As measured by the index, the risk factors for developing dementia are an age of 70 or older, poor scores on two simple cognitive tests, slow physical functioning on everyday tasks such as buttoning a shirt or walking 15 feet, a history of coronary artery bypass surgery, a body mass index of less than 18, and current non-consumption of alcohol. The results do need to be validated in other populations — for example, they have not yet been tested on Hispanics or Asian-Americans.
The tests were described in a presentation at the 2007 International Conference on Prevention of Dementia, in Washington, DC.
http://www.eurekalert.org/pub_releases/2007-06/uoc--stp060707.htm

May 2007

Personality changes may help detect Lewy bodies dementia

Dementia with Lewy bodies is the second most common neurodegenerative cause of dementia. It shares characteristics with both Alzheimer's and Parkinson's disease, but some medications used to treat Alzheimer's patients are potentially dangerous for people with dementia with Lewy bodies. Early diagnosis is therefore important. A new study has found that people with dementia with Lewy bodies often display passive personality changes some time before cognitive deficits are evident, offering hope that a simple personality test might help diagnosis.
The study was published in the May 29 issue of Neurology. Full reference
http://www.eurekalert.org/pub_releases/2007-05/aaon-pcm052107.htm

November 2006

New dementia screening tool detects early cognitive problems

A new screening tool for dementia — the Saint Louis University Mental Status Examination (SLUMS) — appears to work better in identifying mild cognitive problems in the elderly than the commonly used Mini Mental Status Examination — particularly for the more educated patients. It takes a clinician about seven minutes to administer the SLUMS, which supplements the Mini Mental Status Examination by asking patients to perform tasks such as doing simple math computations, naming animals, recalling facts and drawing the hands on a clock. The SLUMS is available at this link http://medschool.slu.edu/agingsuccessfully/pdfsurveys/slumsexam_05.pdf
The study appeared in the November issue of the American Journal of Geriatric Psychiatry. Full reference
http://www.eurekalert.org/pub_releases/2006-11/slu-nds103006.htm

September 2005

More sensitive tests for predicting Alzheimer's

The first study used data from 119 participants in the Longitudinal Aging Study Amsterdam. The memory test scores of those who two years later developed Alzheimer's were compared with the scores of those who stayed healthy. Three tests were very good at predicting who would later develop Alzheimer's: a Paired-Associate Learning Test, which cued participants to recall five semantically related and five semantically unrelated pairs of words; a Perceptual Identification Task, which measured how fast participants read aloud words briefly presented on a computer screen; a Visual Association Test, which cued participants to recall six line drawings of common objects that had been presented earlier in an illogical interaction with another object or cue. On the word-pair memory test, people destined to develop Alzheimer's disease didn't do any better when words were related than when they weren't, suggesting they’d already lost deep semantic knowledge. On the word-reading test, word repetition didn't help high-risk participants to perform better, a sign that implicit learning was impaired. The popular Mini Mental Status Exam (MMSE), a test mainly sensitive to episodic memory, was not as good a predictor.
In the second study, a dichotic listening task, which measures how well people process information when they hear one thing in the left ear and another in the right ear, was found to also be predictive of Alzheimer’s, confirming that people have problems with selective attention very early in the disease.
The studies appear in the September issue of Neuropsychology. Full reference 2
Full text of the both articles is available at www.apa.org/journals/releases/neu195629.pdf
and www.apa.org/journals/releases/neu195687.pdf
http://www.eurekalert.org/pub_releases/2005-09/apa-pfm092105.htm

July 2005

Early warning signs of Alzheimer's show up years before official diagnosis

A meta-analysis of 47 studies of Alzheimer's disease has revealed that people can show early warning signs across several cognitive domains years before they are officially diagnosed, confirming that Alzheimer's causes general deterioration and tends to follow a stable preclinical stage with a sharp drop in function. People at the preclinical stage showed marked preclinical deficits in global cognitive ability, episodic memory, perceptual speed, and executive functioning; along with somewhat smaller deficits in verbal ability, visuospatial skill, and attention. There was no preclinical impairment in primary memory. There is no clear qualitative difference between the normal 75-year old and a preclinical Alzheimer’s sufferer; instead it seems that the normal elderly person, the preclinical Alzheimer’s person, and the early clinical Alzheimer’s patient represent three instances on a continuum of cognitive capabilities.
The findings appeared in the July issue of Neuropsychology. Full reference
http://www.eurekalert.org/pub_releases/2005-07/apa-ews072505.htm

January 2004

More sensitive test norms better predict who might develop Alzheimer's disease

Early diagnosis of Alzheimer's is becoming more important with new medical and psychological interventions that can slow (but not stop) the course of the disease. Given this, it is suggested that more sensitive testing may be necessary for highly intelligent people, who, on average, show clinical signs of Alzheimer's later than the general population. Once they show such signs, they decline much faster. A study of 42 older people with IQ's of 120 or more, used two different test norms to forecast problems: the standard norm, derived from a large cross-section of the population, or an adjusted high-IQ norm that measured changes against the individual's higher ability level. The raised cutoffs predicted that 11 of the 42 individuals were at risk for future decline – compared with standard cutoffs, which indicated they were normal. True to the former prediction, three and a half years later, nine of those 11 people had declined. Six of those went on to develop mild cognitive impairment (MCI), a transitional illness from normal aging to a dementia (of which one type is Alzheimer's). Five of these individuals have since received a diagnosis of Alzheimer's disease, two years after this study was submitted. It is also suggested that, at the other end of the scale, those with below-average intelligence have the potential for being misdiagnosed as 'demented' when they are not, and the norms should be adjusted downwards accordingly.
This finding is reported in the January issue of Neuropsychology. Full reference
http://www.eurekalert.org/pub_releases/2004-01/apa-mst122903.htm

New method of distinguishing Alzheimer's from Lewy body dementia

Looking at specific changes in alertness and cognition may provide a reliable method for distinguishing Alzheimer's from dementia with Lewy bodies (DLB) and normal aging. Four characteristics significantly distinguished patients with DLB from persons with Alzheimer’s and normal elderly controls: daytime drowsiness and lethargy despite getting enough sleep the night before; falling asleep two or more hours during the day; staring into space for long periods and episodes of disorganized speech. "For the normal elderly control group, one or two of these behaviors was found in only 11 percent of the group. For the patients with AD, one or two of these behaviors were not uncommon, but over 63% of the patients with DLB had three or four of these behaviors.” DLB accounts for as much as 20 to 35% of the dementia seen in the United States.
The study appeared in the January 27 issue of Neurology. Full reference
http://www.eurekalert.org/pub_releases/2004-01/ama-nmo010804.htm

September 2003

Brief telephone questionnaire screens for early signs of dementia

Researchers have developed a brief telephonic questionnaire that helps distinguish between persons with early signs of dementia and persons with normal cognitive function. The questionnaire provides a way to reach out to persons with dementia whose impairment otherwise may go undetected until substantial cognitive deterioration has occurred. The questionnaire consists of a test of delayed recall and 2 questions that ask whether the person needs help with remembering to take medications or with planning a trip for errands. It is estimated that of 100 people who score positive on this test, 42 will actually have cognitive impairment. In other words, this does not provide a diagnosis of Alzheimer’s, but provides evidence that further evaluation is required. The rate of false positives compares favorably to other types of screening tests. A further study is underway to confirm the validity and reliability of the test.
The report was published in the August issue of the Journal of Clinical Outcomes Management. Full reference
http://www.eurekalert.org/pub_releases/2003-09/twc-btq091603.htm

January 2003

Verbal memory tests predict dementia

The Longitudinal Aging Study Amsterdam tested the memories of a large group of elderly people on two occasions, two years apart. Performance on the memory tests was then compared between those who developed dementia during those two years and those who did not. It was found that those who later were found to have dementia were scarcely better at remembering word pairs clearly linked in meaning (for example, pipe - cigar) than word pairs without such a link (for example nail - butter), on the first test. (those who not have dementia two years later did, as is usual, benefit from such a link in meaning). In addition, those in the early stage of dementia did not benefit from the repeated presentation of words. The results suggest a means by which elderly people in the early stages of dementia can be identified, which is important because the drugs used to inhibit dementia only work in the earliest stages of the disease.
This was revealed in doctoral research by the neuropsychologist Pauline Spaan from the University of Amsterdam.
http://www.eurekalert.org/pub_releases/2003-01/nofs-mtp012403.htm

August 2002

Verbal memory test best indicator of who will have Alzheimer's disease

A meta-analysis of 31 studies involving a total of 1,144 Alzheimer's patients and 6,046 healthy controls, supports the use of the California Verbal Learning Test in predicting future Alzheimer’s type dementia. Long delay recall and percent recall were the best predictors, with executive function type measures also being predictive but less so than both the long and short delay memory tests. Changes in the hippocampus were the best volumetric or neuroimaging measure but in general volumetric measures were less sensitive to preclinical stages of the dementia than were the neuropsychological tests. It should be noted that a decline in various types of memory, especially verbal episodic memory, is also observable in normal elderly; the crucial factor in determining a pre-dementia state lies in the size of the memory deficit.
Their study was presented in Chicago at the 110th Annual Convention of the American Psychological Association (APA) on August 25. Reference
http://www.eurekalert.org/pub_releases/2002-08/apa-vmt081302.htm

April 2002

Early diagnosis of Alzheimer's

An analysis of data from 40 participants enrolled in a long-term study at the UCSD Alzheimer’s Disease Research Center (ADRC) found that "paper-and-pencil" cognitive skills tests administered to normal subjects averaging 75 years of age contained early signs of cognitive decline in those subjects who later developed Alzheimer’s disease. All participants were symptom-free when they took the test. The differences were quite subtle - only some performance measures were affected. http://www.eurekalert.org/pub_releases/2002-04/uoc--trs040502.htm

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