We searched the Cochrane library (1990–January, 2010), Medline (1990–January, 2010), and Embase (1990–January, 2010) for terms associated with the epidemiology, pathogenesis, diagnosis, treatment, and modifiable risk factors for Alzheimer's disease. For epidemiology we used the following terms: “prevalence OR incidence OR rates OR frequency” AND “dementia, Alzheimer's disease”. In the first instance we preferred systematic reviews and Delphi consensus. For pathogenesis, we used the terms “genes
SeminarAlzheimer's disease
Section snippets
Epidemiology
The cost of caring for the increasing number of people with dementia continues to rise and thus accurate estimates of dementia prevalence are needed. Recent systematic reviews of epidemiological studies have provided comprehensive estimates of dementia prevalence. A WHO report1 estimated that dementia contributed 11·2% of years spent living with a disability in people over 60 years old—more than stroke, cardiovascular disease, and cancer. In 2005, Alzheimer's Disease International convened an
Pathogenesis
The two core pathological hallmarks of Alzheimer's disease are amyloid plaques and neurofibrillary tangles. The amyloid cascade hypothesis suggests that deposition of amyloid β (Aβ) triggers neuronal dysfunction and death in the brain (figure 1). In the original hypothesis, this neuronal dysfunction and death was thought to be a toxic effect of the total amyloid load. As knowledge of pathological changes in Alzheimer's disease increased, research focused on more specific alterations in Aβ
Diagnosis and biomarkers
An accurate diagnosis of dementia enables the detection of potentially treatable disorders that contribute to cognitive impairment, such as depression, vitamin deficiencies, and hypothyroidism, and allows patients and their families to plan their future life and finances, including advance directives and optimum treatment and care. With the prospect of development of disease-modifying drugs, early and accurate diagnosis and the ability to provide a prognosis is essential. Improvement of
Treatment
To effectively treat Alzheimer's disease, patients and families should be involved as soon as the diagnosis is made. The ability of patients to correctly use money, medications, transportation, and home appliances should be assessed, and information, services, and support should be provided to help patients and their families to live well with dementia. Concomitant medical conditions and polypharmacy can exacerbate cognitive decline and increase the risk of cerebrovascular disease and therefore
Risk and protective factors
At present, reduction of the risk of developing Alzheimer's disease depends mostly upon lifestyle changes and improved treatment or prevention of medical conditions that confer additional risk. A database of that assess environmental risk factors for Alzheimer's disease is available online. There is a large amount of data about potential risk factors for Alzheimer's disease, including age,2 genetics,13 and head injury.108 Here, we focus on modifiable risk factors. Table 4 summarises the
Search strategy and selection criteria
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