Neurodegenerative disease: a different view of diagnosis

Neurodegenerative diseases have traditionally been defined as clinicopathol ogical entities. Although this has been a productive paradigm in terms of t he development of treatment strategies, molecular genetic approaches have r evealed that there is overlap between different entities in pathogenic mech anisms. In this article, it is argued that neurodegenerative disease should also be thought of as the consequences of sequential biochemcial processes , and that some parts of these processes appear to operate in more than one disease entity. Defining these pathways and, in particular, developing an appreciation of the commonalities between different disease, should aid in the development of therapies that are effective in several diseases.