SYMPTOMS AND SIGNS IN DEMENTIA - SYNERGY AND ANTAGONISM

This paper addresses the synergy and antagonism between symptoms and s igns among 2,914 elderly Canadians diagnosed in 15 categories, includi ng no cognitive impairment, cognitive impairment but no dementia, mild , moderate and severe forms of Alzheimer's disease and vascular dement ia, 4 subtypes of possible Alzheimer's disease, Parkinson's dementia, unspecified other dementias and unclassified dementias. Attention is p aid to the relationships between symptoms and signs rather than conven tional analyses which assume independent signs. We demonstrate that de mentia progression and specific aetiologies have characteristic patter ns of decline and destruction from the strong synergy that exists betw een symptoms and signs among the population with no cognitive impairme nt. These findings have potential implications for the incorporation o f new diagnostic criteria into existing databases.