Dealing with Dementia: A Guide to Alzheimer's Disease and Other Dementias
Dealing with Dementia: A Guide to Alzheimer's Disease and Other Dementias
eBook
Available on Compatible NOOK devices, the free NOOK App and in My Digital Library.
Related collections and offers
Overview
Product Details
| ISBN-13: | 9781741152753 |
|---|---|
| Publisher: | Allen & Unwin Pty., Limited |
| Publication date: | 09/01/2004 |
| Sold by: | Barnes & Noble |
| Format: | eBook |
| Lexile: | 1440L (what's this?) |
| File size: | 1 MB |
About the Author
Read an Excerpt
Dealing with Dementia
A Guide to Alzheimer's Disease and Other Dementias
By Brian Draper
Allen & Unwin
Copyright © 2004 Brian DraperAll rights reserved.
ISBN: 978-1-74115-275-3
CHAPTER 1
WHAT IS DEMENTIA?
We live in an ageing world. Over the last century life expectancy in Australia has increased from around 55 years to 81.3 years in women and from 52 years to 75.6 years in men. With more people living beyond their allotted 'three-score and ten' years, age-related conditions including osteoarthritis, osteoporosis, cataracts, stroke, cancer, coronary artery disease and dementia have increasingly impacted upon the health of our community. Of these conditions, dementia is the condition that evokes the greatest fear in those contemplating the prospect of a lengthy old age. The possibility of becoming mentally incompetent, forgetful and dependent, in other words senile, can be very disturbing.
DEFINING DEMENTIA
First, let me clarify a few terms. 'Dementia' is a term used medically to describe a syndrome (set of symptoms) that is caused by many different diseases. These include Alzheimer's disease, vascular dementia and dementia with Lewy bodies. An analogy is the term 'cancer', which is used to describe any malignant tumour but is not itself a specific disease. The answer to the frequently posed question 'What is the difference between Alzheimer's disease and dementia?' is that, in a sense, there is no difference — Alzheimer's disease is one of the many different types of dementia.
The dementia syndrome is defined as an acquired decline in memory and thinking (cognition) due to brain disease that results in significant impairment of personal, social or occupational function. Other brain functions that are affected include orientation, comprehension, calculating ability, learning capacity, language, judgement, reasoning and information processing. While there are some notable exceptions, as I discuss later, dementia is usually of gradual onset and progressive. The World Health Organization (WHO) guidelines recommend that these symptoms and impairments be evident for at least six months before a confident diagnosis can be made. While most dementias are currently irreversible, this does not mean that dementia is untreatable. Its progression (course) can often be influenced and many symptoms can be ameliorated. As I discuss in later chapters, major advances have occurred over the last decade in this area.
Most dementing illnesses are progressive, and early symptoms and problems differ markedly from those in later stages. This may simply be a matter of degree — for example, mild memory impairment moving to profound memory impairment. Other symptoms and problems usually develop later in the course of the illness, urinary incontinence being one example. While it is customary to describe dementia in stages, there is overlap between stages and it may not always be easy to state precisely which stage a person has reached. The first stage is a 'pre-dementia' stage, also named by some researchers 'mild cognitive impairment'. Currently we are unable to identify accurately and reliably what it constitutes. The next three stages, as commonly described to carers during a diagnostic assessment, are 'early' or 'mild', 'moderate' or 'middle' and 'late' or 'severe' dementia, respectively. The final stage, 'advanced dementia', is usually found only in nursing home residents. The stages should be regarded as a guideline rather than as a sacrosanct statement about the person's progress (see Table 1.1).
HOW DOES DEMENTIA DIFFER FROM NORMAL AGEING?
Unlike dementia, the concept of normal ageing is poorly understood. Many of the accompaniments of ageing that result in disabilities in recent times have become treatable, which challenges the notion that they are inevitable features of the physiological ageing process and suggests that they may be considered pathologic conditions. Efforts to characterise mental changes intrinsic to normal ageing are fraught with difficulty, with terms such as 'benign senescent forgetfulness', 'age-associated memory impairment' and 'age-associated cognitive decline' being used and now generally reflect the extremes of normal ageing rather than describing a precursor of pathologic ageing.
We acquire knowledge through an active cognitive processing of information that involves thinking, learning and remembering; it is known as fluid intelligence. Fluid intelligence tends to decline with age. Short-term memory wanes to a degree, but in contrast to a person with dementia who tends to forget a whole experience the normal older person will only forget parts of the experience. For example, where the person with dementia might forget altogether having been to the cinema, the normal older person might just forget some details of the film. New learning becomes more difficult for the normal older person, the ability to solve novel problems declines and the speed of mental processing slows. There is a speed — accuracy trade-off, however, with the normal older person tending to make fewer errors.
There is also an age-related tendency to have some increased difficulty in word-finding and remembering names — a situation that most of us have experienced as having a word 'on the tip of the tongue'. In most cases the missing word appears a bit later without prompting. Associated anxiety about not getting the word out may often magnify the problem. In addition, those people who are more 'tongue-tied' than others and have always had some difficulties in expressing themselves find that the ageing process exacerbates this tendency.
The accumulation as one ages of all the knowledge and products of previous cognitive processes is known as 'crystallised intelligence'. Crystallised intelligence does not decline in normal ageing; rather, it often increases with maturity and brings greater wisdom. It is one of the reasons that societal elders are held in high regard and hold senior positions in most cultures. There is no precise point at which normal age-related cognitive changes can be said to become a pathological entity (disease), and there is considerable debate on the issue in the scientific community. There are, however, some warning signs. Normal age-related decline takes place over decades, so decline over a shorter time, months or a few years, is liable to be pathological.
This is particularly the case if the person's functional performance has declined relative to their peers and they are unable to adapt to maintain functioning in normal life.
WHAT ARE THE MAIN TYPES OF DEMENTIA?
Alzheimer's disease is the most common type of dementia in most countries in the world, the main exceptions being Japan and China where vascular dementia predominates. Alzheimer's disease accounts for about 50 to 60 per cent of dementia cases, sometimes occurring in combination with other dementias. Vascular dementia is the next most common, accounting for 15 to 20 per cent of cases. Mixed Alzheimer's-vascular dementia is probably more widespread than clinical diagnoses would suggest, with some postmortem studies suggesting that it might involve as much as 25 per cent of dementia cases. Over the past decade, dementia with Lewy bodies has become increasingly recognised and is said to account for up to 20 per cent of cases, though it would seem that many of these cases also have Alzheimer's disease. Frontotemporal dementia, which includes Pick's disease, occurs in approximately 10 per cent of cases and is particularly common in younger age groups.
Numerous other conditions can cause dementia, but most of them are rare. Conditions such as alcohol abuse, hypothyroidism, vitamin B deficiency and Parkinson's disease are regularly found in persons with dementia, but in most cases the main cause is Alzheimer's disease or vascular dementia. Well-known rare causes of dementia include brain tumours, normal pressure hydrocephalus, progressive supranuclear palsy, cerebral vasculitis and brain trauma. In younger age groups, Human Immunodeficiency Virus (HIV)-related disorders are a more prominent cause, though it should be stressed that in most cases other HIV-related disorders have been previously diagnosed and the dementia occurs late in the course of the disease.
HOW COMMON IS DEMENTIA?
To date over 100 studies worldwide have reported on the prevalence of dementia. Most have been undertaken in developed countries. Professor Tony Jorm and colleagues from the Australian National University in Canberra pooled data from 22 studies and found that the prevalence of dementia doubled every 5.1 years from the age of 60. Applying these rates to the estimated Australian population in 2000 would translate to the figures in Table 1.2, with an overall prevalence of approximately 155 500 persons, revealing that dementia is an age-related condition and its occurrence under the age of 60 is quite rare. While there have been no Australian studies, research from the United States suggests that there are likely to be only around 1300 persons with dementia in the 50 — 59 age group in Australia, and a further 1000 under the age of 50.
IS DEMENTIA BECOMING MORE COMMON?
The simple answer to this question is 'yes', but the increase is basically due to the ageing of the population, not to any innate changes in the risk of developing dementia. As more people survive or avoid early and mid-life illnesses such as cardiac and infectious diseases, they live to an age where they are at higher risk of dementia. This is accentuated by the increasing numbers of persons aged over 85 years — the age group at greatest risk.
There is no evidence from the recent past, in studies from Sweden or the USA, to suggest any significant change in the risk of developing dementia at any particular age. In other words, the incidence (the number of new cases developing in a defined time period) of dementia is only increasing due to these population changes. Thus a person aged 70 in 2003 appears to have a similar risk of developing dementia as a person aged 70 had in 1983. What is not known is whether there have been any changes compared with a hundred or more years ago, and whether the incidence will change in 20 years or more remains to be seen. The impact on rates of dementia of altering various lifestyle risk factors, as described in Chapters 2 and 3, is also unknown. Statistically, if it were possible to simply delay the onset of dementia by a year or two, its prevalence would drop by tens of thousands.
One factor that may impact upon the prevalence of dementia is the recent introduction of cholinesterase-inhibitor drugs such as Aricept, Reminyl and Exelon (see Chapter 7) now being prescribed for Alzheimer's disease. While their long-term effects are unknown, these agents appear to slow the progress of the disease for around twelve to eighteen months in approximately 50 — 60 per cent of patients. It has been hypothesised that dementia symptoms will initially be reduced but that eventually, as the disease progresses, there will be a more rapid decline, with death occurring at the same age as without treatment. Most authorities believe that the actual duration of the disease is not likely to be altered by the use of these drugs. But what if it is altered? If the course of the disease is prolonged, the prevalence of dementia will increase simply because more people are surviving with the illness. Thus, the duration of Alzheimer's disease being increased by one year would have a similar but opposite effect to delaying its onset. In other words, the prevalence of dementia cases might increase by some tens of thousands! The only published information to date involves the first-released cholinesterase inhibitor, tacrine, which is now rarely used. Contrary to expectations, it has been shown to reduce mortality in advanced dementia. Before too much is made of this finding, other studies are needed, particularly of the newer agents that now dominate the market. It will be some years before it is known whether these agents have any measurable impact upon disease duration.
Without taking the possible impact of cholinesterase-inhibitor drugs and moderation of known risk factors into account, Tony Jorm and colleagues have estimated the increase in the number of dementia cases in Australia in the period 1995 to 2041. While the total Australian population is projected to increase by 40 per cent, from just over 18 million in 1995 to just over 25 million in 2041, the number of persons aged 65 years and over is projected to increase by 166 per cent, from around 2.15 million in 1995 to 5.72 million in 2041. Dementia cases, however, are projected to increase by 254 per cent, from around 130 000 in 1995 to 459 000 in 2041. This marked increase is mainly attributable to the projected increase in the number of persons surviving to age 80 and beyond.
Such projections are not unique to Australia. Other developed migrant countries such as Canada, the United States and New Zealand will see a similar pattern. Old World European countries with stable populations such as Sweden and the United Kingdom will have less dramatic changes, although the prevalence of dementia will still increase. It is in the developing world where the most dramatic changes will take place. Indonesia, for example, is projected to have a 295 per cent increase in dementia cases between 1990 and 2030. China, India and Latin America will also have particularly marked increases.
WHAT IS THE IMPACT OF DEMENTIA UPON SOCIETY?
The global impact of dementia is growing. According to the WHO World Health Report 2001, dementia was ranked as the thirteenth leading cause in the world of years lived with a disability in 2000. This ranked ahead of such disorders as cerebrovascular disease, HIV/AIDS, diabetes mellitus and cataracts. It was projected that dementia would rapidly increase its contribution to the global burden of disease over the next 20 years, particularly in developed countries.
These global impacts are mirrored in Australia. The Australian Burden of Disease and Injury Study, undertaken by the Australian Institute of Health and Welfare in 1998/99, provides a comprehensive assessment of the amount of ill health and disability, the 'burden of disease', in Australia in 1996. In this study, mortality, disability, impairment, illness and injury arising from 176 diseases, injuries and risk factors were measured using a common tool, the Disability-Adjusted Life Year (DALY). One DALY is a lost year of 'healthy' life. It is calculated from the combination of years of life lost to premature mortality and equivalent 'healthy' years of life lost due to disability.
In 1996 in Australia, dementia was the sixth-ranked leading cause of burden of disease in all ages, accounting for 3.5 per cent of total DALYs. It was ranked fourth in women and tenth in men. Ischaemic heart disease and stroke were the two leading causes of disease burden. In older Australians, dementia ranked third in women and fifth in men. Dementia is the second leading cause of 'healthy' years lost to disability in both men and women of all ages, trailing only depression, which it will overtake by 2016. Dementia was also the sixth leading cause of mortality, and was noted to have one of the largest increases in mortality burden in the period 1981 — 96. This coincides with the increased recognition and more accurate diagnosis of dementia in Australia, rendering it more likely for doctors to include the diagnosis on death certificates. In 2002, it was estimated that dementia cost over 117 000 years of healthy life.
In March 2003, Access Economics released a report prepared for Alzheimer's Australia on the economic impact of Alzheimer's disease in Australia. The report estimated that there were 162 000 people with dementia in Australia in 2002, 6 600 under 65 years old. The total annual estimated costs of dementia were A$6.6 billion; direct health costs were A$3.2 billion, of which A$2.9 billion was spent on residential care. Access Economics estimated that these costs would double by 2010. Real indirect costs were A$2.4 billion, being costs to carers (A$1.7 billion), lost earnings and the mortality burden of dementia sufferers (A$364 million) and the costs of aids and home modifications (A$120 million). There was an additional A$1 billion in transfer costs — foregone taxes, carer payments and other welfare payments.
In the USA a number of estimates have been made of the annual costs of caring for a person with dementia. The costs increase with the severity of dementia, being estimated at approximately A$94 000 for a patient with severe dementia. The total direct and indirect costs of caring for dementia in the USA have been estimated as approximately A$180 — 200 billion per year.
Dementia already has a considerable effect upon the Australian community. The projected massive increase in the number of cases over the next 40 years is likely to further elevate dementia in the list of leading causes of disease burden, though current and future therapies may ameliorate the impact to some degree. In Victoria, dementia has been projected to become the leading cause of disease burden in women and the fifth highest in men by 2016. Such striking increases obviously will have enormous economic consequences, just in meeting the need for more medical, community and residential services to maintain current standards. The dilemma of how to fund such demands from the public purse has been a concern of economists, health care planners and politicians for some time. The move towards self-funded retirement and user-pays principles in provision of services has largely evolved from these projections.
(Continues...)
Excerpted from Dealing with Dementia by Brian Draper. Copyright © 2004 Brian Draper. Excerpted by permission of Allen & Unwin.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.
Table of Contents
Contents
List of illustrations,List of tables,
Preface,
CHAPTER 1 WHAT IS DEMENTIA?,
CHAPTER 2 PREVENTION OF DEMENTIA I,
CHAPTER 3 PREVENTION OF DEMENTIA II,
CHAPTER 4 THE SYMPTOMS AND COURSE OF DEMENTIA,
CHAPTER 5 TYPES OF DEMENTIA,
CHAPTER 6 DEMENTIA ASSESSMENT,
CHAPTER 7 DRUG TREATMENTS,
CHAPTER 8 PSYCHOSOCIAL TREATMENTS,
CHAPTER 9 FAMILIES AND OTHER CARERS,
CHAPTER 10 COMMUNITY CARE SERVICES,
CHAPTER 11 RESIDENTIAL CARE,
CHAPTER 12 ETHICAL AND LEGAL ISSUES,
CHAPTER 13 THE FUTURE,
Appendix 1 Australian telephone helplines,
Appendix 2 Websites,
Appendix 3 Books for carers,
Glossary,
Notes,