The cortical dementias.

A striking accumulation of new technologies and recent diverse research developments open new insight into the nature of primary dementias. The gene of the familial form of Alzheimer's disease was located in the chromosome 21. By further study of the amyloid protein precursor gene, laboratory diagnosis and eventual treatment of Alzheimer's disease may become a reality. This paper reviews and adds perspective to old and new data on the cortical dementias: Alzheimer's disease and Pick's disease.