Progression of Alzheimer's disease: variability and consistency: ontogenicmodels, their applicability and relevance

Much has been learned about the clinical symptomatology of Alzheimer's dise ase (AD) and ontogenic reciprocal relationships in the past few decades. It is now possible to describe and verify inexorable symptomatic sequences an d corresponding temporal relationships. It is also possible to identify mor e variable symptoms in AD. Ontogenic models can be useful in providing a cl earer understanding of the nature of AD symptomatology in terms of both con sistency and variability. These models can also be informative in explicati ng the management needs of AD patients and the treatment possibilities of A D symptoms as well as the etiology of variability in AD symptoms.