BACKGROUND: Research into ageing-related pathology relies not only on exploration of disease aetiology, but also a clear understanding of the normal ageing process. The present study aims to examine the characteristics of elderly subjects who lie on the borderline between normal and pathological ageing. METHOD: Cognitive functioning is examined using computerized neuropsychometric assessment in a population of 833 normal elderly from which a cohort of 397 subjects with sub-clinical @entity73 are followed over three years. Subjects receive a standardized neurological examination and @entity2204 genotypes are established. RESULTS: Analysis of covariance revealed no cross-sectional age differences for syntax comprehension (p = 0.19), articulation (p = 0.46), semantic matching (p = 0.12), reading (p = 0.79), and implicit memory (p = 0.21) while explicit memory, language skills and @entity1957 were found to deteriorate both in the cross-sectional age comparisons and across time. An overall intellectual ability factor, derived from Principal Components Analysis, was found by regression to decline principally in @entity1 with low education, and a high initial IQ level was observed to provide a protective effect over age 75. @entity1 with higher levels of education show relative stability over time on language and secondary memory tasks but deteriorate as rapidly as @entity1 with low education on visuospatial tasks. Five separate patterns of sub-clinical cognitive deficit were isolated by cluster analysis. Two groups, with differing clinical profiles (of which only one manifested the @entity2204 allele), were found to have an increased risk of developing @entity195 (OR = 4.4 and 3.9). A third group had a high prevalence of @entity308 , and the remaining two showed very little change. CONCLUSION: Ageing does not affect all cognitive functions uniformly: a high initial education level slowing rate of decline for certain tasks. Separate patterns of @entity73 are observed in early @entity195 , benign change and changes related to @entity308 . Results suggest the need for more stringent selection of normal control groups.

Establishing the limits and characteristics of normal age-related XXXX .

@entity1 :: ('9606', 'Species') :: ['Persons', 'persons'] @entity308 :: ('MESH:D003866', 'Disease') :: ['depressive illness'] @entity2204 :: ('348', 'Gene') :: ['ApoE4', 'ApoE'] @entity73 :: ('MESH:D003072', 'Disease') :: ['cognitive impairment', 'cognitive change'] @entity1957 :: ('MESH:D019957', 'Disease') :: ['visuospatial skills'] @entity195 :: ('MESH:D000544', 'Disease') :: ['senile dementia']
@entity73 :: (MESH:D003072,Disease) :: ['cognitive decline']
