dementia prevalence

Vascular & Mixed Dementia

alence

Vascular dementia, as its name suggests, is caused by poor blood flow, produced by a single, localized stroke, or series of strokes.

It is the second most common dementia, accounting for perhaps 17% of dementias. It also co-occurs with Alzheimer's in 25-45% of cases. Although there are other types of dementia that also co-occur with Alzheimer's, mixed dementia generally refers to the co-occurrence of Alzheimer's and vascular dementia.

Risk factors

In general, unsurprisingly, vascular dementia has the same risk factors as cerebrovascular disease.

A study1 of 173 people from the Scottish Mental Survey of 1932 who have developed dementia has found that, compared to matched controls, those with vascular dementia were 40% more likely to have low IQ scores when they were children than the people who did not develop dementia. Because this was not true for those with Alzheimer's disease, it suggests that low childhood IQ may act as a risk factor for vascular dementia through vascular risks rather than the "cognitive reserve" theory.

Prevention

The exciting thing about vascular dementia is that it is far more preventable than other forms of dementia. As with risk, as a general rule, the same things that help you protect you from heart attacks and stroke will help protect you from vascular dementia. This means diet, and it means exercise.

A four-year study2 involving 749 older adults has found that the top one-third of participants who exerted the most energy in moderate activities such as walking were significantly less likely to develop vascular dementia than those people in the bottom one-third of the group.

Treatment

Apart from normal medical treatment for cerebrovascular problems, there are a couple of interesting Chinese studies that have looked specifically at vascular dementia.

The herb gastrodine has been used in China for centuries to treat disorders such as dizziness, headache and even ischemic stroke. A 12-week, randomized, double-blind trial3 involving 120 stroke patients who were diagnosed with mild to moderate vascular dementia has found that  gastrodine and Duxil® (a drug used to treat stroke patients in China) produced similar overall levels of cognitive improvement -- although more patients showed 'much improvement' with gastrodine (23% vs 14%).

A Chinese pilot study4 involving 25 patients with mild to moderate vascular dementia found that ginseng compound significantly improved their average memory function after 12 weeks, but more research (larger samples, placebo-controls) is needed before this finding can be confirmed. Five years on I have still not seen such a study.

References: 

  1. McGurn, B., Deary, I.J. & Starr, J.M. 2008. Childhood cognitive ability and risk of late-onset Alzheimer and vascular dementia. Neurology, first published on June 25, 2008 as doi: doi:10.1212/01.wnl.0000319692.20283.10
  2. Ravaglia, G. et al. 2007. Physical activity and dementia risk in the elderly. Findings from a prospective Italian study. Neurology, published online ahead of print December 19.
  3. Tian, J.Z. et al. 2003. A double-blind, randomized controlled clinical trial of compound of Gastrodine in treatment of mild and moderate vascular dementia in Beijing, China. Presented at the American Heart Association's Second Asia Pacific Scientific Forum in Honolulu on June 10.
  4. Tian, J.Z. et al. 2003. Presented at the American Stroke Association's 28th International Stroke Conference on February 14 in Phoenix. Press release

Topics: 

tags problems: 

tags development: 

Dementia with Lewy Bodies

LBD: What is it?

Lewy Body Dementia is so called because the brains of affected people develop abnormal spherical masses of protein, called Lewy bodies, inside nerve cells. Lewy bodies are associated with Parkinson’s disease as well as dementia. Thus Lewy body dementia can refer to both Parkinson’s disease dementia and “dementia with Lewy bodies”. Lewy bodies are also often found in the brains of those with Alzheimer’s disease.

Unlike Alzheimer’s, however, dementia with Lewy bodies characteristically (but not invariably) begins with visual hallucinations.

Prevalence of LBD

Estimates of its prevalence are complicated by the lack of clearly defined clinical criteria, and vary widely. A 2005 review1 concluded that the range probably falls between 0 to 5% in the general population, and from 0 to 30.5% of all dementia cases (the very broad range reflects the confusion between Parkinson’s disease dementia (PDD), dementia with Lewy bodies, and Alzheimer’s where Lewy bodies are present).

How does LBD differ from Alzheimer's & PDD?

A comparison of these three disorders found that cognitive impairment in those with Alzheimer's disease and those with Lewy body dementia was similar, and more severe than in those with Parkinson's disease dementia.

The 1997 study2 also found that a simple test, in which patients are asked to draw and copy a clock face, distinguished those with Alzheimer’s and those with Lewy body dementia — of all the groups, only those with Lewy body dementia had equally poor scores in the “copy” part of the test compared to the “draw” part.

For more information:

Mayo Clinic: http://www.mayoclinic.com/health/lewy-body-dementia/DS00795

Lewy Body Dementia Association: http://www.lewybodydementia.org/

References: 

  1. Zaccai, J., McCracken, C. & Brayne, C. 2005. A systematic review of prevalence and incidence studies of dementia with Lewy bodies. Age and Ageing, 34(6), 561-566.
  2. Gnanalingham, K.K. et al. 1997. Motor and cognitive function in Lewy body dementia: comparison with Alzheimer's and Parkinson's diseases. Journal of Neurology, Neurosurgery, and Psychiatry, 62, 243-252.

Topics: 

tags problems: 

tags development: 

Dementia: A general introduction

alence of dementia

Dementia is estimated1 to afflict over 35.5 million people worldwide -- this includes nearly 10 million people in Europe, nearly 4.4 million in North America, nearly 7 million in South and Southeast Asia, about 5.5 million in China and East Asia and about 3 million in Latin America.

The estimated prevalence for over 60s is 4.7% worldwide. Because this is a disorder of age, prevalence is of course greatly affected by the proportion of people reaching their senior years. Hence the prevalence is higher in the more developed countries: the estimated prevalence in Western Europe and North America is 7.2% and 6.9% respectively, compared to 2.6% in Africa.

What kinds of dementia are most common?

The prevalence of the various dementia types is a complicated story. Certainly Alzheimer's disease is by far the most common type of dementia, accounting for perhaps 70% of all dementias (although a 2006 study13 suggested that non-Alzheimer dementias were as common as Alzheimer's — however this was based on dementia among military veterans). The second most common dementia is almost certainly vascular dementia, which may account for some 17% of dementias. However, the actual numbers are made uncertain by the fact that these two dementias often occur together.

At minimum, around a quarter of Alzheimer's cases have been found, on autopsy, to also have vascular pathology; this proportion reaches higher levels when the samples are not restricted to dementia clinics. One such community-based study2, for example, found 45% of the Alzheimer's cases also showed significant vascular pathology. Another, U.K., study3 found a similar proportion (46%).

Another, large long-running, study14 has found that only 30% of people with signs of dementia had Alzheimer’s disease alone. 42% had Alzheimer’s disease with cerebral infarcts (strokes) and 16% had Alzheimer’s disease with Parkinson’s disease (including two people with all three conditions). Infarcts alone caused another 12% of the cases. Vascular dementia caused another 12%.

Although there are other types of dementia that also co-occur with Alzheimer's, mixed dementia generally refers to the co-occurrence of Alzheimer's and vascular dementia.

The other important dementia type that co-occurs with Alzheimer's at a high rate is dementia with Lewy bodies, also considered to be one of the most common dementias (although, due to inconsistent criteria, estimates of its actual prevalence vary wildly). It is estimated to co-occur with Alzheimer's pathology around half the time. At a lesser frequency, but still high, is Parkinson's disease dementia — about 20% of Alzheimer's patients also have Parkinson's disease.

But it is probably fair to say that the distinction between these dementia types is not clear-cut. Lewy bodies are found in a high proportion of both Alzheimer's and Parkinson's patients — the number of cases of 'pure' Lewy body dementia is much smaller. It's been said, in fact, that the main difference between Lewy body dementia and Parkinson's disease dementia lies in the timing — Parkinson's disease dementia will be preceded by at least a year and more likely a number of years, by full-blown Parkinson's disease.

Regardless of the difficulties in establishing clear clinical criteria, however, there is no doubt that Alzheimer's co-occurs with vascular pathology or Lewy body pathology at a startlingly high rate.

One of the problems with clearly distinguishing between these types of dementia is a happy one: vascular and Alzheimer's pathology can be found, at autopsy, in many elderly brains that have not shown symptoms of dementia.

For example, in one community-based study4, in which the median age at death was around 85 for the 209 individuals, 48% had had dementia, of whom 64% showed Alzheimer's pathology. However, 33% of those who had not had dementia showed similar levels of Alzheimer's plaques. Similarly, some amount of tau tangles (another aspect of Alzheimer's pathology) was found in 61% of the demented and 34% of the non-demented individuals. Finally, multiple vascular pathology was found in 46% of the demented group and 33% of the non-demented, and vascular lesions were equally common in both.

And in the large long-running study mentioned earlier14, in those without dementia, brain autopsy revealed the presence of Alzheimer’s in 24% of cases, and infarctions in 18%.

How likely am I to develop dementia?

The question of how likely any person is to develop dementia must begin with estimates of prevalence, but this of course is only the very beginning of the story.

Estimating prevalence is complicated by the fact that dementia is greatly affected by lifestyle, environmental, and genetic factors, and consequently prevalence varies a lot depending on geographic region.

Different dementia sub-types have different causes, and some give a much greater weight to genetic or environmental factors than others. However, the finding that dementia risk is much greater in those with more than one pathology, and that Alzheimer’s pathology with cerebral infarcts is a very common combination, adds to growing evidence that dementia risk might be reduced with the same tools we use for cardiovascular disease such as control of blood cholesterol levels and hypertension.

Age as a factor

The first American study to use nationally representative data5 (rather than extrapolating from regional data) came up with a figure of 13.9% of those aged 71 and older (one in seven). But age of course makes all the difference in the world. The study found 5% of those aged 71 to 79, rising to 37.4% of those age 90 and older.

Although all the dementia types show an increase with age, Alzheimer's is particularly a disorder of age: although the study found only 46.7% of those with dementia in their 70s had Alzheimer's, for those in their 90s, Alzheimer's was the dementia type for 79.5% of them.

An Italian study of over 2000 seniors over 80 years old6 confirms that dementia does indeed keep increasing with age (it had been thought that risk leveled off for those who reached their 90s). The study found that 13.5% of those aged 80 to 84 had dementia, rising sharply to 30.8% of those 85 to 89, 39.5% of those 90 to 94, and 52.8% among those older than 94.

Gender as a factor

A number of studies have found differences between men and women, or between difference ethnicities, but this large, nationally representative study found that, although on the face of it there were race and gender differences, these differences disappeared once age, years of education, and presence of at least one "Alzheimer's gene" was taken into account.

However, an American study of over 900 seniors over 90 years old7 found that women of this age were much more likely to have dementia than men (some 45% of them, compared to 28% of the men), and that the likelihood of having dementia kept increasing with age for the women, but not for the men. Of course, more women than men survive to this age (some two-thirds of the participants were women).

Interestingly, education was protective for the women (the risk of dementia decreasing the more years of education the individual had had) but not for the men. The study participants were not, however, a random sampling -- they all came from the same retirement community, and most were white and of high socioeconomic status. Given that, and considering the times in which they were born, it seems likely that there would be far more variability in educational level among the women than the men. The men, while less likely to develop dementia, did tend to decline faster if they did develop it.

The Italian oldest-old study, too, found more women than men had dementia: across all ages, 25.8% of the women and 17.1% of the men.

These figures don't of course tell us how many develop dementia at those ages. Obviously, survival rates are a factor, and as we saw in the other study, male and female survival rates do vary. The figures for new cases of dementia developing in these age bands were:

  • 6% at 80 to 84 years;
  • 12.4% at 85 to 89 years;
  • 13.1% from 90 to 94 years; and
  • 20.7% among those over 94.

These figures make even more clear what was apparent in the earlier figures: dementia jumps suddenly in the later half of the 80s, and again in the later half of the 90s.

Importantly, however, the incidence of new cases shows us how important the gender difference in survival rates is: the difference in prevalence is much smaller in these terms --9.2% among women and 7.2% among men.

The study, which canvassed everyone in the age group within a specific geographical area and had an 88% response rate, had a ratio of 74 women to 26 men. Because the number of men at the very highest ages was so small, we can't draw any firm conclusions about gender differences at those ages.

The Italian study involves a very different population from that of the American study: Varese is in a heavily industrialised part of northern Italy, with a high immigrant population, and the average amount of education was only 5.1 years.

A review of 26 studies looking at dementia prevalence in Europe8 confirmed rates for men rising from 1.8% in the 65-69 years age range up to 30% in the over 90 years age group, and for women rising from 1.5% to 30% in the 80-85 years age band. However (and confirming the American study), rates in the oldest old for women rose to over 50% in those over 95 years.

Early onset of dementia

The average age at the onset of dementia is around 80 years. Early-onset dementia is defined arbitrarily (and variably) as occurring before 60-65. Early-onset cases have been estimated to make up about 6-7% of all cases of Alzheimer's disease, and though a lot of attention has been given to them, only about 7% of early-onset cases are in fact familial9.

Familial cases involve mutations in specific genes (the APP or presenilin genes); they do not include what is popularly referred to as the "Alzheimer's gene" — variants of APOE. A 1995 study10 calculated that a person with no family history of Alzheimer's disease who has an e4 allele has a lifetime risk of 29%, compared to a risk of 9% if they don't have an e4 allele. In other words, if you don't have any of the Alzheimer's risk genes, or any family history, you only have a 9% risk of developing Alzheimer's, and even if you do have the "Alzheimer's gene", your chance of not getting Alzheimer's is still over 70%. Your risk does, however, go up dramatically if both your APOE alleles are e4.

A large study11 found, however, that there were both ethnic and gender differences for the risk of this genetic factor. The effect of having an e4 allele was much greater among Japanese compared to Caucasian, and greater for Caucasian compared to African American and Hispanic. Additionally, the effect of having an e4 allele becomes less significant after 70.

There is evidence12 that the age of onset for both Alzheimer's and Parkinson's diseases, for those genetically disposed, is controlled by genes on chromosome 10.

References: 

  1. From the 2009 World Alzheimer's Report: http://www.alz.co.uk/research/worldreport/
  2. Lim A, Tsuang D, Kukull W, et al. 1999. Cliniconeuropathological correlation of Alzheimer’s disease in a community-based case series. Journal of the American Geriatric Society, 47, 564-569.
  3. Neuropathology Group of the Medical Research Council Cognitive Function and Ageing Study (MRC CFAS). 2001. Pathological correlates of late-onset dementia in a multicentre, community-based population in England and Wales. Lancet, 357, 169-175.
  4. Langa, K.M., Foster, N.L. & Larson, E.B. 2004. Mixed Dementia: Emerging Concepts and Therapeutic Implications. JAMA, 292(23), 2901-2908.
  5. Plassman, B.L. et al. 2007. Prevalence of Dementia in the United States: The Aging, Demographics, and Memory Study. Neuroepidemiology, 29, 125-132. 
  6. Lucca, U. et al. 2009. Risk of dementia continues to rise in the oldest old: The Monzino 80-plus Study. Presented on July 14, 2009, at the annual International Conference on Alzheimer's Disease in Vienna. http://www.alz.org/icad/documents/abstracts/abstracts_prev_ICAD09.pdf
  7. Corrada, M.M. et al. 2008. Prevalence of dementia after age 90: Results from The 90+ Study. Neurology, 71 (5), 337-343.
  8. Reynish, E. et al. 2009. Systematic Review and Collaborative Analysis of the Prevalence of Dementia in Europe. Presented on July 14, 2009, at the annual International Conference on Alzheimer's Disease in Vienna. http://www.alz.org/icad/documents/abstracts/abstracts_prev_ICAD09.pdf
  9. Nussbaum, R.L. & Ellis, C.E. 2003. Alzheimer's Disease and Parkinson's Disease. New England Journal of Medicine, 348 (14), 1356-1364. http://content.nejm.org/cgi/content/full/348/14/1356#R23
  10. Seshadri S, Drachman DA, Lippa CF. 1995. Apolipoprotein E epsilon 4 allele and the lifetime risk of Alzheimer's disease: what physicians know, and what they should know. Archives of Neurology, 52, 1074-1079. http://tinyurl.com/ya7vss7
  11. Farrer LA, Cupples LA, Haines JL, et al. Effects of age, sex, and ethnicity on the association between apolipoprotein E genotype and Alzheimer disease: a meta-analysis. JAMA 1997;278:1349-1356. http://tinyurl.com/yb9tdju
  12. Li, Y. et al. 2002. Age at Onset in Two Common Neurodegenerative Diseases Is Genetically Controlled. American Journal of Human Genetics, 70, 985-993. Press release
  13. Ross, E.D. et al. 2006. Changing Relative Prevalence of Alzheimer Disease versus Non-Alzheimer Disease Dementias: Have We Underestimated the Looming Dementia Epidemic? Dementia and Geriatric Cognitive Disorders, 22 (4), 273-277.
  14. Schneider, J.A., Arvanitakis, Z., Bang, W. & Bennett, D.A. 2007. Mixed brain pathologies account for most dementia cases in community-dwelling older persons. Neurology, published ahead of print June 13.

 

Topics: 

tags problems: 

tags development: 

Dementia trend shows later onset with fewer years of the disease

  • A large study shows that the falling rates of dementia reflect later onset coupled with shorter time spent with the dementia.

A large study using data from the famous Framingham Heart Study has compared changes in dementia onset over the last three decades. The study found that over time the age of onset has increased while the length of time spent with dementia has decreased.

The study involved 5,205 participants from the Framingham Original and Offspring cohorts. Four 5-year periods anchored to different baseline examinations (participants have been examined every four years) were compared. These baseline years are (on average, because participants’ schedules are different): 1978, 1989, 1996, 2006. Participants were those who were aged 60 or older and dementia-free at the start of a time period. There were at least 2000 participants in each time period. In total, there were 371 cases of dementia, and 43% of dementia cases survived more than 5 years after diagnosis.

It was found that the mean age of dementia onset increased by around two years per time period, while age at death increased by around one year. Length of survival after diagnosis decreased over time for everyone, taken as a whole, and also for each gender and education level, taken separately. Survival was almost 6 years in the first time period, and only three years in the last. But the mean age of onset was 80 in the first period, compared to over 86 in the last.

However, the changes haven’t been steady over the 30 years, but rather occurred mostly in those with dementia in 1986–1991 compared to 1977–1983.

Part of the reason for the changes is thought to be because of the reduced risk of stroke (largely because of better blood pressure management), and the better stroke treatments available. Stroke is a major risk factor for dementia. Other reasons might include lower burdens of multiple infections, better education, and better nutrition.

https://www.eurekalert.org/pub_releases/2018-04/uoth-dts042318.php

Reference: 

Source: 

tags development: 

Topics: 

tags problems: 

One in 4 elderly Australian women have dementia

  • A new estimation technique has raised the dementia rates for Australian women from 20% to 26%.

In Australia, it has beens estimated that 9% of people aged over 65, and 30% of those aged over 85 have dementia. However, these estimates are largely based on older data from other countries, or small local samples.

A new technique based on an ecological method for estimating species population size has been used to estimate dementia rates in the Australian population. The study used 16 years of data from 12,432 Australian women born between 1921 and 1926 who participated in the Women's Health Australia study. Survey data was linked to aged care assessments, the National Death Index, the Pharmaceutical Benefits Scheme, and hospital admissions data to find any instance where the women participating in the study were diagnosed with dementia. This additional data helped overcome the problem of such studies, where participants often just drop out, and the cause isn’t known.

Applying the ecological technique to all this data led to the conclusion that an additional 728 women with dementia had not been identified, increasing the 16 year prevalence from 20.4 to 26.0%. Breaking this down by age, we have:

  • 70-74: 0.3%
  • 75-79: 3.7%
  • 80-84: 16.6%
  • 85+: 31%

https://www.eurekalert.org/pub_releases/2017-03/uoq-oif031617.php

Reference: 

Source: 

tags development: 

Topics: 

tags problems: 

Rates of new dementia cases may be falling

  • Data from the very long-running Framingham Heart Study adds to evidence that, for those with at least a high school education, the rate of dementia is declining. Improved cardiovascular health and treatment appears to be an important factor in this decline.

As we all know, people are living longer and obesity is at appalling levels. For both these (completely separate!) reasons, we expect to see growing rates of dementia. A new analysis using data from the long-running Framingham Heart Study offers some hope to individuals, however.

Looking at the rate of dementia during four distinct periods in the late 1970s, late 1980s, 1990s, and 2000s, using data from 5205 older adults (60+), the researchers found that there was a progressive decline in the incidence of dementia at a given age, with an average reduction of 20% per decade since the 1970s (22%, 38%, and 44% during the second, third, and fourth epochs, respectively).

There are two important things to note about this finding:

  • the decline occurred only in people with a high school education and above
  • the decline was more pronounced with dementia caused by vascular diseases, such as stroke.

The cumulative risk over five years, adjusted for age and gender, were:

  • 3.6 per 100 persons during the first period (late 1970s and early 1980s)
  • 2.8 per 100 persons during the second period (late 1980s and early 1990s)
  • 2.2 per 100 persons during the third period (late 1990s and early 2000s)
  • 2.0 per 100 persons during the fourth period (late 2000s and early 2010s).

Part of the reason for the decline is put down to the decrease in vascular risk factors other than obesity and diabetes, and better management of cardiovascular diseases and stroke. But this doesn't completely explain the decrease. I would speculate that other reasons might include:

  • increased mental stimulation
  • improvements in lifestyle factors such as diet and exercise
  • better health care for infectious and inflammatory conditions.

The finding is not completely unexpected. Recent epidemiological studies in the U.S., Canada, England, the Netherlands, Sweden and Denmark have all suggested that “a 75- to 85-year-old has a lower risk of having Alzheimer’s today than 15 or 20 years ago.” Which actually cuts to the heart of the issue: individual risk of dementia has gone down (for those taking care of their brain and body), but because more and more people are living longer, the numbers of people with dementia are increasing.

http://www.futurity.org/dementia-rates-decline-1119512-2/

http://www.scientificamerican.com/article/is-dementia-risk-falling/

Reference: 

Source: 

tags development: 

Topics: 

tags problems: 

How dementia risk varies among ethnic groups

  • A very large U.S. study looking at ethnic differences in dementia risk, has found that African-Americans show the highest rates of dementia, followed by blacks and American Indian/Alaska Natives, then Latinos and whites, with Asian-Americans having the lowest rates.

A study involving 14 years of health records from more than 274,000 Northern Californians has assessed the relative dementia risk of six different ethnicities.

The average annual rate of dementia was:

  • 26.6 cases per 1,000 for blacks
  • 22.2 cases per 1,000 for American Indians/Alaskan Natives
  • 19.6 cases per 1,000 for Latinos and Pacific Islanders
  • 19.3 cases per 1,000 for whites
  • 15.2 cases per 1,000 for Asian Americans.

But this is an annual rate, not particularly useful at a practical level. How do these numbers convert to lifetime risk? Statistical calculations estimate that among those who reach age 65 dementia-free, the following percentages of each ethnicity will develop dementia in the next 25 years:

  • 38% of blacks
  • 35% of American Indians/Alaskan Natives
  • 32% of Latinos
  • 30% of whites
  • 28% of Asian Americans
  • 25% of Pacific Islanders (this is probably the least reliable number, given the small number of Pacific Islanders in the sample).

The study population included 18,778 African-Americans, 4543 American Indians/Alaskan Natives, 21,000 Latinos, 206,490 white Americans, 23,032 Asian-Americans, and 440 Pacific Islanders.

http://www.eurekalert.org/pub_releases/2016-02/kp-lsf021016.php

Reference: 

tags problems: 

Topics: 

Rate of dementia has decreased for African-Americans

A long-running study comparing African-Americans and Nigerians has found the incidence of dementia has fallen significantly over two decades among the African-Americans, but remained the same for the Nigerians (for whom it was lower anyway).

The study enrolled two cohorts, one in 1992 and one in 2001, who were evaluated every 2–3 years until 2009. The 1992 cohort included 1440 older African-Americans (70+) and 1774 Nigerian Yoruba; the 2001 cohort included 1835 African-Americans and 1895 Yoruba. None of the participants had dementia at study beginning.

The overall standardized annual incidence rate was 3.6% for the 1992 African-American cohort, and 1.4% for the 2001 cohort. For the Yoruba, it was 1.7% and 1.4%, respectively.

It's suggested that one reason for the improvement among African-Americans may be medications for cardiovascular conditions. Although both groups had similar rates of high blood pressure, this was recognized and treated in the American group but not in the Nigerian.

As you can see, African-Americans in the earlier cohort were more than twice as likely as Africans to develop dementia. Their decrease has brought them into line with the African rate.

Although the rate of new cases of dementia decreased, the African-Americans enrolling in 2001 had significantly higher rates of diabetes, hypertension and stroke, but also higher treatment rates, than the African-Americans who enrolled in 1992.

The finding offers hope that treatment can offset the expected increase in dementia resulting from the rise in lifestyle diseases.

http://www.eurekalert.org/pub_releases/2015-08/iu-sn080415.php

Reference: 

Source: 

Topics: 

tags problems: 

Tracking preclinical Alzheimer's progression

New research supports the classification system for preclinical Alzheimer’s proposed two years ago. The classification system divides preclinical Alzheimer's into three stages:

Stage 1: Levels of amyloid beta begin to decrease in the spinal fluid. This indicates that the substance is beginning to form plaques in the brain.

Stage 2: Levels of tau protein start to increase in the spinal fluid, indicating that brain cells are beginning to die. Amyloid beta levels are still abnormal and may continue to fall.

Mynd: 

tags problems: 

tags development: 

Over 90% of dementia cases in China are undetected

A survey of 7,072 older adults in six provinces across China, with one rural and one urban community in each province, has identified 359 older adults with dementia and 328 with depression. There were only 26 participants who had doctor-diagnosed dementia reported and 26 who had doctor-diagnosed depression. Overall, 93% of dementia cases and 93% of depression were not detected.

Undetected dementia was strongly associated with low socioeconomic status such as a low educational and occupational class, and living in a rural area.

Mynd: 

tags problems: 

tags development: 

Pages

Subscribe to RSS - dementia prevalence