Brain Aging in the Oldest-Old

Table 1

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

	Cognitively impaired young-old subjects	Cognitively impaired oldest-old subjects
Senile plaques	Higher amyloid load but lower correlation with neurone loss and cognitive status	Lower amyloid load but better correlation with neurone loss and cognitive status
	Early and significant CA2-3 involvement	Invasion of anterior CA1 field
	Early and significant EC involvement	Mild invasion of EC
	Significant inferior temporal and frontal associative cortex involvement with increasing dementia	Relative sparing of inferior temporal and frontal associative cortex
Neurofibrillary tangles	Less parietal and cingulate cortex involvement	More parietal and cingulate cortex involvement
	With advancing dementia, quick invasion of CA1 andspread to adjacent associative cortex	With advancing dementia, lower invasion of CA1 and less spread to associative cortex
	Higher strength of association with dementia	Lower strength of association with dementia
	High interindividual variability
Neurones	Loss of pyramidal neurones in CA1 and EC	Less neurone loss in CA1 Possibly, relative sparing of EC neurones
	More NFT-related neurone loss	Less NFT-related neurone loss

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