[How to define Alzheimer's disease].

Alzheimer's disease, which was considered to be a rare disease in subjects aged under 65 until the seventies/eighties, has become a very common disease affecting mostly older subjects. Many consider that it is important to review the meaning of the eponym "Alzheimer's disease", and a revolution, quite literally, is likely to occur. The role of vascular lesions in the onset of dementias among older subjects is widely acknowledged; considering those dementias as Alzheimer's disease may have negative consequences for patient management. Indeed, vascular lesions can be prevented and treated, while Alzheimer's lesions cannot. It may be justified to use "Alzheimer syndrome" instead of "Alzheimer's disease" when vascular risk factors and, all the more so, vascular lesions are present. Significant progress has been made in the understanding of the pathological proteins involved in Alzheimer's disease, as well as their effects on neurons and synapses. However, the etiology of the disease is still unknown, except in the rare hereditary cases, and there is no cure for Alzheimer's disease at present. Clinical research is progressing, and diagnostic criteria for the pre-dementia stage of Alzheimer's disease were suggested. In France, the outstanding Alzheimer plan 2008-2012 should play an important role in enhancing the understanding of Alzheimer's disease, Alzheimer's syndromes and related disorders.