Non-Alzheimer degenerative dementias.

The explosion of research aimed at exploring degenerative dementias in the past 20 years has produced a great deal of knowledge concerning not only Alzheimer's disease but also other conditions referred to as non-Alzheimer degenerative diseases. The conditions reviewed here fall broadly into two main categories: diseases with focal (lobar) atrophy and diffuse Lewy body disease. These conditions, which are described more and more often in centers around the world, represent entities different from Alzheimer's disease not only from a clinical and pathological viewpoint, but also in terms of genetics and perhaps even in terms of therapeutic responses. In view of the numerous therapeutic trials currently underway, the distinction between Alzheimer's disease and non-Alzheimer degenerative diseases has acquired new importance.