The cause or causes of Alzheimer’s diseases are not yet known. However, most experts agree that Alzheimer’s, like other common chronic diseases, develops as a result of multiple factors rather than a single cause. These factors include a variety of brain changes that begin as many as 20 years before symptoms appear. Increasingly, the time between the initial brain changes of Alzheimer’s and the symptoms of advanced Alzheimer’s is considered by scientists to represent the “continuum” of Alzheimer’s. At the start of the continuum, the individual is able to function normally even though there are changes in the brain. Further along the continuum, the brain can no longer compensate for the increased neuronal damage caused by brain changes, and
