Session Title: Alzheimer's Disease (AD) including Non-Cognitive Aspects
ALZHEIMER´S DISEASE AND PARKINSON´S DISEASE
Measures of the prevalence of Alzheimer´s disease differ depending on the diagnostic criteria used, the age of the population surveyed, and other factors, including geography and ethnicity. Excluding persons with clinically questionable dementia, Alzheimer´s disease has a prevalence of approximately 1 percent among those 65 to 69 years of age and increases with age to 40 to 50 percent among persons 95 years of age and over. Although the mean age at the onset of dementia is approximately 80 years early-onset disease, defined arbitrarily and variously as the illness occurring before the age of 60 to 65 years, can occur but is rare. In one community-based study in France, the prevalence of early-onset disease (defined by an onset before the age of 61 years) was 41 per 100,000; thus, early-onset cases make up about 6 to 7 percent of all cases of Alzheimer´s disease.About 7 percent of early-onset cases are familial, with an autosomal dominant pattern of inheritance and high penetrance. Thus, familial forms of early-onset Alzheimer´s disease, inherited in an autosomal dominant manner, are rare; however, their importance extends far beyond their frequency, because they have allowed researchers to identify some of the critical pathogenetic pathways of the disease.