e dementia occurring in younger patients and the dementia occurring in the elderly were manifestations of the same disease.
In Alzheimer's disease there appears to be a deficiency of at least one major neurotransmitter within the brain. A post mortem evaluation of Alzheimer's is the only definitive means of diagnosing the presence of this deficiency: "Because brain biopsies--the only clear means of identifying the neural changes caused by the disease--are rarely performed, definitive diagnosis must wait until after a patient dies" (1:12). In living patients, a clinical diagnosis of Alzheimer's disease is valid only after repeated exclusion of other possible diseases which cause dementia, such as high blood pressure, diabetes or alcoholism. The patient's history must be obtained and blood tests performed, followed by an EEG (electroencephalogram) or CAT (computerized axial tomography) of the brain. In scanning the brain, physicians look for enlarged dark areas typical of the presence of Alzheimer's disease. These dark regions indicate impaired blood flow and diffuse atrophy of the brain. Only after all other treatable causes are excluded can physicians make the diagnosis of Alzheimer's: "Very early dementia is often difficult to discriminate from normal age-related changes on the initial evaluation and requires follow-up to establish the rate of progression of the impairment to make the diagnosis" (5:5).
A study by researchers from Rush University in Chicago, the Centers for Disease Control in Atlanta, and Harvard University indicates that the rate of Alzheimer's disease may be higher than previously assessed (2:B3). Researchers studied a group of 3,600 people 65 and older in Boston beginning in 1982. Memory tests were administered to the subjects over a two-year period. Representative samples from the groups who performed poorly on the tests and those who performed well on the test were followed and periodically teste...