Table 1: Alzheimer’s disease pathology in the cognitively impaired young-old versus oldest-old.

Cognitively impaired young-old subjectsCognitively impaired oldest-old subjects

Senile plaquesHigher amyloid load but lower correlation with neurone loss and cognitive statusLower amyloid load but better correlation with neurone loss and cognitive status

Early and significant CA2-3 involvementInvasion of anterior CA1 field
Early and significant EC involvementMild invasion of EC
Significant inferior temporal and frontal associative cortex involvement with increasing dementiaRelative sparing of inferior temporal and frontal associative cortex
Neurofibrillary tanglesLess parietal and cingulate cortex involvementMore parietal and cingulate cortex involvement
With advancing dementia, quick invasion of CA1 andspread to adjacent associative cortexWith advancing dementia, lower invasion of CA1 and less spread to associative cortex
Higher strength of association with dementiaLower strength of association with dementia

High interindividual variability

NeuronesLoss of pyramidal neurones in CA1 and ECLess neurone loss in CA1 Possibly, relative sparing of EC neurones
More NFT-related neurone lossLess NFT-related neurone loss

NFT: neurofibrillary tangles; CA: Cornu Ammonis; EC: entorhinal cortex.