Early Diagnosis of Alzheimer Disease

In 1984, a task force sponsored by the Alzheimer Disease (AD) and Related Disorders Association and by the National Institute of Neurological Diseases and Stroke established a set of working criteria for the clinical diagnosis of probable AD. With these criteria, the clinical diagnosis of AD has an accuracy of approximately 85 percent. Consequently, this communication will review several laboratory methods that could ultimately aid the clinician in the diagnosis of early or even preclinical AD. The general utility of these methods has been hotly debated and has been the subject of a recent position paper from the American Academy of Neurology (1989). AD is associated with a deficit in neo- and allocortical cholinergic neurotransmission that is roughly correlated with the degree of neuronal degeneration in the cholinergic basal forebrain.