Unit 3 Alzheimer’s Dementia Alzheimer’s Disease

Alzheimer’s disease (AD) is the most common cause of dementia, and the number of affected individuals in the world population is near epidemic proportions,1 more than 35 million people. Epidemi-ologists predict a doubling of patients every 20 years, thus by 2050 the number affected will soar to 115 million! AD is the sixth leading cause of death and the only cause among the top 10 that cannot be prevented or cured.2 Each year there are 7.7 million new cases of dementia, or a new case every 4 seconds. The cost of AD is staggering. In 2010 the cost worldwide was estimated to be US $604 billion, a figure that includes direct costs for medical care plus the cost of informal care provided by family and others.3 If dementia care were a country, it would be the world’s 18th largest economy; were it a company, it would be the world’s largest, with annual revenue exceeding those of Wal-Mart ($414 billion) and Exxon Mobil ($311 billion).3 Diagnosing AD is challenging and is typically made by exclud-ing other conditions associated with cognitive changes. Computed tomography (CT) and magnetic resonance imaging (MRI) are used to rule out tumor, cerebrovascular disease, and normal pressure hy-drocephalus and to detect disease-associated atrophy in the medial temporal lobe and amygdalohippocampal system.4 Increasingly, physicians are using biomarker data to make the diagnosis, and when paired with behavioral data, accuracy is high. Diagnostic Criteria for AD In 2011 a collaborative effort between the Alzheimer’s Association and the National Institute on Aging resulted in revised diagnostic criteria.5 The core criteria for all-cause dementia are cognitive and behavioral symptoms that: (1) interfere with the ability to function 1