Alzheimer's disease

Alzheimer's disease is a complex and fascinating entity, clinically and neurobiologically. Although originally described as a form of accelerated aging in an article that emphasized neuropathology, it is now considered a specific age-related disease entity, at whatever age it occurs. It is the most common cause of the dementia syndrome, probably the fourth most common cause of death in the United States and is likely to become more common as the population ages. The course is typically an insidious onset of cognitive and behavioral impairment progressing more or less steadily over years to profound disability. The classic pathologic changes are Alzheimer plaques, neurofibrillary tangles, and loss of subcortical cells, including particularly the cholinergic cells of the nucleus basalis complex. The functional disability can be correlated with the site and extent of brain damage, but why these cells deteriorate and die is not known. Diagnosis depends on identifying the dementia syndrome in a patient whose course is compatible with Alzheimer's disease and in whom no other factors adequate to explain the dementia are found. NIH consensus diagnostic criteria are now available. Care is symptomatic optimal care of intercurrent illness, and pharmacologic, behavioral, and social "splints" to maximize the function of the remaining brain. Specific treatments are still in the realm of research, and both clinical and basic research on this challenging disorder are active and accelerating.